Make "aliases" show up in "arc get-config" help
Make "aliases" show up in "arc get-config" help

Summary: Fixes T11758. This was one some spooky magic but is more-or-less a normal config setting now.

Test Plan:
  - Ran `arc get-config`, saw help about "aliases".
  - Ran `arc set-config aliases`, saw guidance about using `arc alias`.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T11758

Differential Revision: https://secure.phabricator.com/D16745

r4nt/arcanist,Khan/arcanist,uber/arcanist,fivestars/arcanist,codelabs-ch/arcanist,r4nt/arcanist,folsom-labs/arcanist,chundongwang/arcanist,Khan/arcanist,phacility/arcanist,chundongwang/arcanist,folsom-labs/arcanist,phacility/arcanist,chundongwang/arcanist,codelabs-ch/arcanist,uber/arcanist,Khan/arcanist,uber/arcanist,uber/arcanist,aik099/arcanist,fivestars/arcanist,codelabs-ch/arcanist,folsom-labs/arcanist,r4nt/arcanist,codelabs-ch/arcanist,folsom-labs/arcanist,chundongwang/arcanist,codelabs-ch/arcanist,phacility/arcanist,aik099/arcanist,aik099/arcanist,fivestars/arcanist,aik099/arcanist,phacility/arcanist,fivestars/arcanist,Khan/arcanist,phacility/arcanist,r4nt/arcanist