Refactor modules into contexts (#78)

* [WIP] break out a few contexts, start refactoring fast index modules

* [WIP] more contexts, this time around slow indexing and downloads

* [WIP] got all tests passing

* [WIP] Added moduledocs

* Built a genserver to rename old jobs on boot

* Added a module naming check; moved things around

* Fixed specs

mix.exs

@@ -59,6 +59,7 @@ defmodule Pinchflat.MixProject do
       {:nimble_parsec, "~> 1.4"},
       {:mox, "~> 1.0", only: :test},
       {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
+      {:credo_naming, "~> 2.1", only: [:dev, :test], runtime: false},
       {:ex_check, "~> 0.14.0", only: [:dev, :test], runtime: false},
       {:faker, "~> 0.17", only: :test},
       {:sobelow, "~> 0.13", only: [:dev, :test], runtime: false}