Add possibility to discuss/about translation at project's level

I worked two weeks ago about words used in Weblate's translation in French and exchanged emails with another contributor. We settled a few rules and did corrections. It would be great to be able to write this in Weblate, to make it open to any current or future contributors.

I think adding the comment mechanism to project would be great. By comment mechanism, I'm thinking about possibility to make comment about one language or for every languages.
It may make sense to have it on component level, but I feel like it would add too much places to comment/discuss.