docs: add contribute new locale instruction

[reslear]

📚 Description

📝 Checklist

• [x] All commits follow the Conventional Commit format
• [x] The PR's title follows the Conventional Commit format

[dargmuesli]

Closing as stale.

[reslear]

not stale

[dargmuesli]

When would you expect to answer my questions above?

[reslear]

I'm sorry, I don't see your questions.)

[dargmuesli]

Oh ok, I've resubmitted them. I think they should show now. Sorry for the confusion :pray:

[dargmuesli]

:tada: This PR is included in version 7.5.1 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket:

[dargmuesli]

:tada: This PR is included in version 8.0.0-beta.4 :tada:

The release is available on:

• npm package (@beta dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: