Make sigil doctests more readable in the source
Add field retrieval of records via `record(record())`
Fix `mix archive` in changelog
Merge pull request #2516 from alco/sigil-docs

Make sigil docs more readable in the source
Merge pull request #2517 from ericmj/record-fields

Add field retrieval of records via `record(record())`
Support aliases in Mix.Task.run/2
Document and list aliases on help --names
Update docs and CHANGELOG