Better AppStream metadata

[AFCMS]

Fix #14647

To do

This PR is Ready for Review

• Rename .appdata.xml to .metainfo.xml (.metainfo.xml is the recommended file name)
• Import description translations from .desktop
• Translate long description in french
• Fix typo in french .desktop description
• Use HTTPS URLs for screenshots
• Add support info for mouse, keyboard, gamepad and touch
• Add support info for supported screen size
• Add support info for offline use
• Use the launchable tag to reference the .desktop file, remove .desktop from the top id (no idea why it was like that, didn't see it anywhere in the spec)
• Add category and keywords
• Add basic developer infos (is it OK?)
• Fix URLs for bugtracker and donation
• Make first paragraph of long description longer? (>80 characters) Not a big deal IMO.

How to test

Try running:

flatpak run --command=flatpak-builder-lint org.flatpak.Builder appstream ./misc/net.minetest.minetest.metainfo.xml

or this (less strict):

appstreamcli validate ./misc/net.minetest.minetest.metainfo.xml

Warning

With the renaming of the AppStream file, the Flathub manifest will need to be updated to reflect the change I think

[AFCMS]

I have added a value to display_length.

The goal is to make it appear as supported for both PC and mobile devices, so I picked 360 which is the value used by GNOME Calculator.

I have also added a tag to display the offline use of Minetest possible.

[AFCMS]

I consider this PR as finished, IMO the last TODO item isn't really important.

The last thing to check is the contact email, but don't know what to put here obviously.

[sfan5]

ruben and c55 are also listed here: https://github.com/minetest/minetest/security/policy
So one of them would be a good candidate.

[Zughy]

@AFCMS updates?

[okias]

ACK on appdata/metainfo transition. Look reasonable with requested changes.

[AFCMS]

Updated the descriptions to mention the fact that Minetest is a game platform.

English and French should be good, for other translations I just used DeepL and can't really validate those.

If some people with knowledge of the respective languages could verify the translations that would be great.

The last thing that may be done in this PR is the contact email change, but I obviously can't do much about it.

[okias]

I guess @celeron55 would be good choice, as @sfan5 pointed https://github.com/minetest/minetest/security/policy

[AFCMS]

Updated the contact email to c55

[grorp]

I still don't like the short description tbh. It's a lot of words which don't really make sense together.

Multiplayer infinite-world block sandbox game platform

Minetest is ... what? An infinite-world ... or an infinite-world block sandbox ... or a sandbox game ... or a game platform? Reduced version with more focus:

Block-based multiplayer game platform

Also, regarding the German translation:

Mehrspieler-Sandkasten-Spielplattform für unendliche Welten

This highlights the "infinite worlds" aspect too much.

Minetest ist eine unendliche Blocksandkasten-Spielplattform.

"Blocksandkasten-Spieleplattform"? What's that?