message: add stabilization guide first draft
diff: @@ -33,6 +33,9 @@ PR's against [rust-lang-nursery/rust-forge].
  process for bug fixes that may cause existing code to stop
  compiling.
  +* [So you want to stabilize a feature?](stabilization-guide): Describes
  + the procedure for stabilizing features in rustc.
  +
  * [Bots, websites and infrastructure](infrastructure.html). A catalog
  of the IRC bots, websites and other infrastructure used by the
  project, what they do, and who maintains them (i.e. who to contact
  