Wrong link on the contributing page to website discussions

[ann0see]

URL
https://github.com/jamulussoftware/jamuluswebsite/blob/translate3_7_0/wiki/en/en-Contribution.md#jamulus-website

We should link this to the main discussion forum.

[96RadhikaJadhav]

@ann0see Can I work on it?

[ann0see]

Yes sure, you can open a PR to the translate3_7_0 branch which fixes this for all pages in all languages! The files are in /wiki/[languagecode]/ as far as I know.

Thank you very much!

[ann0see]

German should already be ok.