home.md

-This is GHC's GitLab instance. GitLab has replaced Trac and Phabricator as the center of GHC's development community.
+This is GHC's Wiki.
 
 You may wish to see the [table of contents](./index) to get a sense for what is available in this Wiki.
 
+Everyone can edit this wiki.  Please do so -- it easily gets out of date.  But it has lots of useful information in it.
+
 # Quick Links
 
 * [GHC Home](https://www.haskell.org/ghc/) GHC's home page
@@ -15,7 +17,8 @@ You may wish to see the [table of contents](./index) to get a sense for what is
   * [Migration Guide](/migration) Migrating code between GHC releases
   * [Working conventions](/contributing#contributing-to-ghc) How should I do X?
   * [Building Guide](/building/#building-and-porting-ghc) Build GHC from source.
-  * [Coding style guidelines](/commentary/coding-style) Please follow these guidelines!
+  * [Coding style guidelines](/commentary/coding-style) Please follow these guidelines.
+  * [Trees that grow (TTG)](/implementing-trees-that-grow) Guidance on how GHC uses the TTG style.
   * [Debugging](/debugging#debugging) How to debug the GHC.
   * [Commentary](/commentary/#the-ghc-commentary) Explaining the GHC source code.