DOC: Add how to contribute translations in crowdin

[tkoyama010]

Brief description of what is fixed or changed

DOC: Add how to contribute translations in crowdin

[netlify]

✅ Deploy Preview for numpy-org ready!

Name	Link
🔨 Latest commit	b01e7b8
🔍 Latest deploy log	https://app.netlify.com/sites/numpy-org/deploys/64edd8d4b30a3100080e566a
😎 Deploy Preview	https://deploy-preview-681--numpy-org.netlify.app/contribute
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[steppi]

Thanks @tkoyama010. I like the idea of giving more info on how to join the project, but to me this gives the impression that anyone can join Crowdin and start translating. What we want people to know is how to get in touch with a translation manager. After that I'll handle the process, inviting and on-boarding people. I'm going to think a bit about what info we should put here and would appreciate any input and advice you have to offer.

[tkoyama010]

Thank you for your comment. crowdin has an approval feature to join the project, how about using that? There is also a function to contact the translation manager.

[melissawm]

Hi folks, now that our workflow has been updated to multiple sites/languages, how about adding a link to the general docs at https://scientific-python-translations.github.io/translate?