Add support for "fixes" result type

This amazing plugin, https://github.com/r7kamura/danger-suggester should be provided abstractions built into core

IT maybe be something you can attach to an inline message? I'm a little unsure

Start by reading the linked danger-suggester plugin and comparing its “fixes” result type with the abstractions currently provided by danger-js core. Determine whether the result should attach to an inline message, then define the supported behavior and verify that core exposes it consistently.

Written by the indexing model from the issue text.