PWAsForFirefox: download ældre versioner

Added
- A new documentation website (#335):
- An ability to update package versions without editiong files (#193, thanks to @JJRcop):
Fixed
- Add compatibility with Firefox 116, fixing missing settings (#378).
- Add compatibility with Firefox 117.

Fixed
- Broken installation instructions page (#368).

Added
- An option to launch web apps on the system login (#273).
- An option to launch web apps on the browser launch (#273).
Changed
- Updated warning about merging web apps on Linux.
- Updated dependencies.
Fixed
- Manifest downloading should be more reliable (#318).
- Window decorations should no longer be visible on fullscreen (#312).
- Permissions and notifications widgets should no longer have weird layout (#321).