[REGISTRY] Directory and file creation + initial README

Added the directory registry to src/shared/utils, added front-end .h and .cpp file
Initial README created with the Frontend specifications

src/shared/utils/Registry/README.md

+# Skyward Registry
+
+### Goal and purpose
+
+Skyward Registry is a Skyward project to develop a configuration saving
+mechanism into persistent (flash memory) and non persistent memories (RAM).
+
+Its purpose is to save the configurations for the rocket and retrieve them after
+a reboot or momentary CPU issues and transient events.
+
+The need of such sw development has its roots in some events in which
+the reboot of the rocket, and therefore its configuration, lent to a misconfiguration, taking defaults values. This caused the propulsion chamber's valves
+to open with wrong timing and therefore causing a misfire.
+Therefore, it is of the utmost importance to save the configuration and avoid default and hardcoded values.
+
+## The front-end
+
+### Invocation example
+In this case we take as example a ficticious configuration entry (NAME which has as value datatype a float)
+#### Set
+float value = 1.3;
+
+if(set(Configurations::NAME_CONF, value))
+ { /*! correctly set */
+}
+
+if(set(NAME(value))) {/*! correctly set */}
+
+#### Get
+float value;
+
+float default = 1.35;
+
+if(get(Configurations::NAME_CONF, &value)) {/*! Getted the value */}
+
+value = getOrSetDefault(Configurations::NAME_CONF, default);
+
+### Goals
+
+| Goal |  Description  |
+|:-----|:--------:|
+| G1 | The configuration will be saved in memory |
+|G2 | It will be possible to set the value of a particular configuration entry|
+|G3 | It will be possible to get the value of a particular configuration entry |
+|G4 | It will be possible to inspect the configured entries |
+|G5 | More data types can be used as value for the different configurations entries |
+|G6 | There will be a protection against changes to the configuration during flight |
+|G7 | No dynamic allocations will be executed during the flight |
+|G8 | The registry will offer a persistent configuration saving |
+|G9 | It will be possible to verify the integrity of the configuration|
+|G10 | It will be possible to explore the current configuration |
+|G11 | Type safeseness and thread safeness is guaranteed |
+
+### Assumptions
+The front-end, FE, considers some important assumptions about the usage of such sw component.
+This assumptions are about the method call, the order of operations and other assumptions on the usage.
+Such assumptions considers the actual necessarities for Skyward Registry and might not be true in future.
+
+| Assumption |  Description  |
+|:-----|:--------:|
+|A1 | The FE is constructed and instantiated once, a single time|
+|A2 | The FE does saves and retrieves a single configuration from the registry |
+|A3 | The FE is called before the flight for instantiation and registry check |
+|A4 | The FE is correctly armed before the flight |
+|A5 | The FE disarming is not used during flight |
+|A6 | The caller considers the return of the get and set methods
+
+### Requirements
+
+| Requirments |  Description  |
+|:-----|:--------:|
+|R1 | The interface must allow setting a value for the specific configuration entries |
+|R2 | The interface must allow getting a specified value for a   configuration entries |
+|R3 | The interface must allow the correct data types for the   specifics entries |
+|R4 | The interface must not allocate memory during the  flight phase |
+|R5 | The interface must not change the configuration entries during flight phase |
+|R6 | The interface does save the configuration entries using the back-end components |
+|R7 | The FE must manage concurrent get/set by multiple threads (Thread safety)|
+|R8 | The FE must manage concurrent arm/disarm by multiple threads  (Thread safety)|
+|R9 | The FE must allow exploration of the actual configuration|
+|R10 | The FE should be able to control the configuration state via the back-ends (existing, corrupted, non existing)|
+
+### Interface methods
+- set:  A setter method is in need to ensure R1. This method should allow 
+    insert a value for a specific configuration entry while guarantee the different data types for the values (R3).
+    
+- get:  A getter method is in need to ensure the visibility of the configuration. 
+    Such method should get a value for a specified configuration entry
+
+ - arm:  An "arm" method which guarantees no memory allocations and no changes to the configuration are in place
+    until a "disarm" method. It is an important functionality to ensure a "safe" memory configuration during flight.
+
+ - disarm: A "disarm" method, to disable the stable and "safe" configuration mode of the registry to allow again 
+    allocations and settings on the configuration.
+
+ - isConfigured: A method to explore the actual status of the configuration, if there is an existing one in memory or not.
+
+ - isConfigurationEmpty: A method to know if there is an existing configuration or if it is empty
+
+ - isConfigurationCorrupted: A method to know if there is an existing configuration in the registry but corrupted memory.
+
+- configuredEntries: A method which returns the already existing entries of the configuration as a set.

src/shared/utils/Registry/RegistryFrontEnd.cpp

+/* Copyright (c) 2023 Skyward Experimental Rocketry
+ * Author: Nicolò Caruso
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+namespace Boardcore{
+
+    
+}
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src/shared/utils/Registry/RegistryFrontEnd.h

+/* Copyright (c) 2023 Skyward Experimental Rocketry
+ * Author: Nicolò Caruso
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+#include <utils/Debug.h>
+
+namespace Boardcore
+{
+
+/**
+ * Macro for the creation of the used datastructures, they will be created by
+ * using CONF(NAME_ENTRY, type) The data structure will contain its
+ * configuration enum entry, the datatype and the value of the configuration.
+ */
+#define CONF(name, dataType)                       \
+    struct name                                    \
+    {                                              \
+        using type = dataType;                     \
+        dataType value;                            \
+        ConfigurationEnum enumIndex = name##_CONF; \
+    };
+
+/**
+ * These are the possible configuration entries structures, with their value
+ * type */
+CONF(RIG_TIMING1, float)
+CONF(RIG_TIMING2, int)
+
+/**
+ * Configuration enum, includes all the possible configurations accepted by the
+ * front-end for saving. Each own has its data structure, created by using the
+ * macro. By adding one configuration also an equivalent enum named with pedix
+ * _CONF must be added*/
+enum ConfigurationEnum
+{
+    RIG_TIMING1_CONF,
+    RIG_TIMING2_CONF
+};
+
+/**
+ * This
+ */
+class RegistryFrontEndInterface
+{
+public:
+    virtual ~RegistryFrontEndInterface(){};
+
+    virtual
+};
+
+}  // namespace Boardcore
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