ArchaicHammer 2022-05-11: add fr to info.xml and fr.js

[ArchaicHammer]

No description provided.

[nursoda]

@ArchaicHammer Thanks for your contribution! I wait for one russian string, then publish a minor release.

[nursoda]

I slightly modified the source strings and adapted translations, including yours.
Please verify whether I got it right using Deepl, or send corrections as PR. Thanks a lot!

I'd like to contact all translators by e-mail. If that's OK with you, please send me an email message stating to which email address I shall send my future "heads up" messages.

I'd also probably switch the app translations to transifex. If you have any experience on how to do that switch, I ask you to help me do it. If you have time for this, please let me know (in your email message).

Last but not least: Please state if you'd also be supporting your translation if we were to switch to transifex, if you'd only use GitHub PRs or what else opinion you have on how to support your translation.