Add IDEA files.

.idea/.gitignore

.idea/deployment.xml

.idea/encodings.xml

.idea/gcc-explorer.iml

.idea/jsLibraryMappings.xml

.idea/libraries/gcc_explorer_node_modules.xml

.idea/misc.xml

.idea/modules.xml

.idea/scopes/scope_settings.xml

.idea/vcs.xml

.idea/webResources.xml

.jshintrc

LICENSE

Notes.md

README.md

app.js

c-preload/preload.c

d/demangle.d

lib/properties.js

lib/sources/browser.js