Add instance and extension list links to About

public/md/about.md

@@ -8,9 +8,14 @@ privacy. The source is available on GitHub at <https://github.com/zedeus/nitter>
 * Prevents Twitter from tracking your IP or JavaScript fingerprint
 * Uses unofficial API (no developer account required)
 * AGPLv3 licensed, no proprietary instances permitted
-* Lightweight (for @nim_lang, 36KB vs 580KB from twitter.com)
+* Lightweight (for [@nim_lang](/nim_lang), 36KB vs 580KB from twitter.com)
 * Native RSS feeds
 
+Nitter's GitHub wiki contains a list of
+[instances](https://github.com/zedeus/nitter/wiki/Nitter-Instances) and
+a [browser extensions](https://github.com/zedeus/nitter/wiki/Extensions)
+maintained by the community.
+
 ## Why use Nitter?
 
 It's basically impossible to use Twitter without JavaScript enabled. If you try,