Add mocha to Projects Using Knip

See mochajs/mocha#5042

packages/docs/src/content/docs/index.mdx

@@ -83,6 +83,7 @@ Using Knip in a commercial project?<br />Please consider [sponsoring me][1]!
 - [freeCodeCamp][12]
 - [Grafana][13]
 - [Nuxt][14]
+- [Mocha][29]
 - [Release It!][15]
 - [Svelte][16]
 - [Query][17], [Table][18] (TanStack)
@@ -159,3 +160,4 @@ Special thanks to the wonderful people who have contributed to this project:
 [27]:
   https://www.joshuakgoldberg.com/blog/speeding-up-centered-part-4-unused-code-bloat/
 [28]: https://tech.basemachina.jp/entry/introduction-knip
+[29]: https://github.com/mochajs/mocha