doc & example additions

2 jobs for common_app in 3 minutes and 20 seconds
Status Job ID Name Coverage
  Lint
failed #115242622
lint

00:03:20

 
  Test
skipped #115242623
unit-testing
 
Name Stage Failure
failed
lint Lint
==> ex_machina
Compiling 5 files (.ex)
Generated ex_machina app
==> phoenix_ecto
Compiling 6 files (.ex)
Generated phoenix_ecto app
==> pleroma
** (Mix) You're trying to run :pleroma on Elixir v1.6.4 but it has declared in its mix.exs file it supports only Elixir ~> 1.7.3
ERROR: Job failed: exit code 1