Convert Mix.Tasks.Compile.Elixir.ManifestCompiler from a GenServer to an Agent
Improve IEx description
Generate docs per app
Update repo links
Merge pull request #2341 from pma/master

Convert Mix.Tasks.Compile.Elixir.ManifestCompiler from GenServer to Agent
No need to name the agent
Ensure variables do not leak on callbacks
Add docs for @derive