Remove docz from projects (#2679)

I was looking at examples and apparently docz is now archived. The website for `docz.site` is now an OnlyFans page, so I'm assuming you would rather not be a canonical resource for people adopting MDX.

Signed-off-by: Kyle Kelley <rgbkrk@gmail.com>

Author: rgbkrk

docs/community/projects.mdx

@@ -27,7 +27,6 @@ This page lists community projects using MDX.
 ## Libraries
 
 * [ok-mdx][]: Browser-based MDX editor
-* [docz][]: Documentation framework
 * [mdx-deck][]: MDX-based presentation decks
 * [mdx-docs][]: Next-based documentation framework
 * [mdx-paper][]: MDX-based research articles
@@ -54,8 +53,6 @@ This page lists community projects using MDX.
 
 [demoboard]: https://frontarm.com/demoboard
 
-[docz]: https://www.docz.site/
-
 [mdnext]: https://github.com/domitriusclark/mdnext
 
 [mdx-deck]: https://github.com/jxnblk/mdx-deck