Added BACKLOG.md file.

Author: azizk

BACKLOG.md

@@ -0,0 +1,8 @@
+# Backlog
+
+The backlog contains tasks that are planned to be worked on or ideas that may be useful.
+
+* Elixir: allow setting the seed used for `mix test` via a command or similar.
+* Elixir: use ST4's branching feature to improve some rules.
+* Elixir: try to fix the rules that don't work due to the "context sanity limit" error.
+* Elixir: highlight `:atom`, `identifier`, `Module.X`, `M.func/1` in Markdown comments?