Some README tweaks

Author: orta

README.md

@@ -4,6 +4,7 @@ This repo is the source of truth for the GitHub wiki, PRs to this repo are autom
 auto-generated GitHub [repo for the wiki](https://github.com/microsoft/TypeScript.wiki.git). This is done 
 in a GitHub Action in [`.github/workflows/sync.yml`](.github/workflows/sync.yml).
 
+The wiki root is [Home.md](./Home.md).
 
 
 # Contributing