Add back "translations/README_translate.md"

[A-Loot]

What is your feature request regarding to?

README

Other

No response

Is your feature request related to a problem? Please describe.

Would make it easier to update and add translations. Don't know why it was removed in #920

Describe the solution you would like.

Add back (and update) "translations/README_translate.md"

Describe alternatives you have considered.

Currently you'd have to copy and translate the original README.md, which is a bit different (e.g. no Disclaimer, no Note at the top)

Requisites

• This is not a support issue or a question. For any support, questions or help, join our Discord server.
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
• I understand that not filling out this template will lead to the issue being closed.

Additional context.

No response