[Feature Request] Allow translations of Anki manual from within pontoon

[GithubAnon0000]

@NamelessGO mentioned in #335 the following:

The manual could add i18n support, which could lead to more users translating the manual, or at least enable translation systems such as Pontoon and Weblate to help, but not much progress yet

I have a fork where I started to translate the manual into german, but there are some issues:

1. If multiple people work on translating, then we do not rely on a single person to update the docs and translation is much faster.
2. If strings get updated it would be easier to find them and only (re)translate the updated strings. The rest would stay untouched.
3. It would potentially help to make the manuals less outdated.

I don't know how implementing this to pontoon could work in practice. But I'm hoping this would allow us to translate paragraph by paragraph (or sub-topic by sub-topic or similar).

Possibly some strings could be reused from the anki code too. E.g. by using variables that reference the header of the true retention table. So if the anki core / desktop translation changes, the manual would automatically get up to date with the current translation as well.

Would be nice if this could be considered (dae et al).

[abdnh]

Some prior discussion here: ankidroid/ankidroiddocs#101 (comment)