[ReDoc] Made contributing file more complete
[ReDoc] Improved README
[ReDoc] Removed definition of public API
[ReDoc] Added License header in every files
[ReDoc] Added full stop at the end of comments
[ReDoc] Improved app/console documentation
[ReDoc] Updated documentation of the app/console file

The documentation has been updated and the app/console file now manages
the creation of the console output and the PHP version checking.
[ReDoc] Fixed typos
[ReDoc] Updated the host to the DNS
[ReDoc] Fixed typos
[ReDoc] Updated installation documentation

Fixed typos and removed the 'Setting permissions...' section, as they
are already set and git keeps them.
[ReDoc] Removed Formatters tests from the Application
[ReDoc] Improved PHPdoc
[ReDoc] Fixed CS
[ReDoc] Reformatted CHANGELOG
[ReDoc] Added requirements in the README
Merge branch 'feature/re-documentation' into develop
[Disconnect] Checked presence of the connection