feat: Port AboutWindow to AboutDialog (from appdata) ...

List of changes:

adw_show_about_window -> adw_about_dialog_new_from_appdata

A bunch of metainfo/appdata improvements

(partial) Support for a .Devel manifest, I had some issues like the keyboard shortcuts action not being available, so I got rid of it, but the application_id stuff is still there

Add a .gitignore

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stavracas-pc-building-simulator 46.beta

‎‎‎⠀⠀User defined options
⠀⠀⠀⠀prefix: /app

Found ninja-1.11.1 at /usr/bin/ninja