Update README.md

Fix link to meta

Signed-off-by: Eric Hanson <[email protected]>

docs/README.md

@@ -5,13 +5,14 @@
 * The [Quickstart](quickstart.md) covers creating a simple "Hello World" application.
 * The [Cheat Sheet](cheatsheet.md) covers the major patterns needed for creating applications.
 
-## Backend Documentation
+## Backend Modules
 
-* Extensions
-    * [meta](../extensions/meta/)
-    * [bundle](../extensions/bundle/)
-    * [event](../extensions/event/)
-    * [filesystem](../extensions/filesystem/)
-    * [endpoint](../extensions/endpoint/)
-    * [widget](../extensions/widget/)
-    * [semantics](../extensions/semantics/)
+Each backend modules is a PostgreSQL extension, with some documentation:
+
+* [meta](https://github.com/aquameta/meta)
+* [bundle](../extensions/bundle/)
+* [event](../extensions/event/)
+* [filesystem](../extensions/filesystem/)
+* [endpoint](../extensions/endpoint/)
+* [widget](../extensions/widget/)
+* [semantics](../extensions/semantics/)