[Submodules] Use library 'Catch2' (v1.12.2) as submodule

.gitmodules

 [submodule "libs/miosix-kernel"]
 	path = libs/miosix-kernel
-	url = ../../scs/miosix-kernel.git
+	url = ../miosix-kernel.git
 [submodule "libs/tscpp"]
 	path = libs/tscpp
-	url = ../../scs/third-party/tscpp.git
+	url = ../third-party/tscpp.git
 [submodule "libs/mavlink_skyward_lib"]
 	path = libs/mavlink_skyward_lib
-	url = ../../scs/mavlink_skyward_lib.git
+	url = ../mavlink_skyward_lib.git
 [submodule "libs/eigen"]
 	path = libs/eigen
-	url = ../../scs/third-party/eigen.git
+	url = ../third-party/eigen.git
 [submodule "libs/mxgui"]
 	path = libs/mxgui
-	url = ../../scs/third-party/mxgui.git
+	url = ../third-party/mxgui.git
 [submodule "libs/fmt"]
 	path = libs/fmt
-	url = ../../scs/third-party/fmt.git
+	url = ../third-party/fmt.git
+[submodule "libs/Catch2"]
+	path = libs/Catch2
+	url = ../third-party/Catch2.git