message: add .html links
diff: @@ -29,11 +29,11 @@ PR's against [rust-lang-nursery/rust-forge].
  * [The Rust test suite](test-suite.html).
  -* [Rustc bug fix procedure](rustc-bug-fix-procedure): Describes the
  +* [Rustc bug fix procedure](rustc-bug-fix-procedure.html): Describes the
  process for bug fixes that may cause existing code to stop
  compiling.
  -* [So you want to stabilize a feature?](stabilization-guide): Describes
  +* [So you want to stabilize a feature?](stabilization-guide.html): Describes
  the procedure for stabilizing features in rustc.
  * [Bots, websites and infrastructure](infrastructure.html). A catalog
  