Page for i3 ecosystem

[acrisci]

I think we should have a page on the website that keeps a list of all the projects that work with i3 such as statusline generators, ipc libraries, and config template things.

[stapelberg]

I think that’s a good idea. Adding a document (like the user-contributed docs we have) on the /docs page would be a good way to go about it, I think. Can you send a PR of an initial version?