Investigate localisation support

[philpax]

We have users from all around the world that may not be able to work with OWL Control's English text, especially given some of the finer technical details mentioned.

We should investigate how difficult it would be to add localisation support. Basic requirements:

• Not too difficult to implement / maintain. We would probably use something like https://crates.io/crates/i18n-embed
• Some way to detect the use of user-facing English strings; we should make sure that all user-facing text goes through the localisation pipeline
• Choice of language, while defaulting to the user's locale, should be up to the user
• The UI should not break with RTL languages. I imagine this will be a challenge.
• The localisations should be easy to contribute to. We can MTL the initial set, but assume that our users will want to submit their own corrections. I've seen https://crowdin.com/ be used for this; it depends on how much bookkeeping we want to do.

[philpax]

For the MTLing: we can set up a prompt for CC/similar to use with all of the relevant context. We could then write some text for the English localisation, and have CC update the other localisations with enough context to choose the correct wording where it would otherwise be ambiguous.