Merge pull request #152 from mbruzek/master

Adding back the custom Juju markdown for Note
Initial Charm Review Process doc!
Disapprove managed to lose track of an e. Fixed.
Added 1.20.6 release notes.
Added "existing charm" merge proposal section.
Post-initial-feedback commit. Changes some inline code blocks to use less tick marks, removed some unnecessary context regarding some links to improve UX as well as some charmer team reference stuff.
Addition of Code Review section with tips. Clarification of README points, icon / copyright notes, change of double-quotes to backticks, merge info movement and improvement, charm proof command clarification, etc.
Added a missing set of backticks
Merge pull request #153 from sinzui/1.20.6-release-notes

Added 1.20.6 release notes.
Documenting how the harvest mode works.
Merge pull request #155 from katco-/master

Documenting how the harvest mode works.
Clarify that both charmers and those that want to become a charmer need to follow the reviewers guidelines.
Added info to help point reviewers in the best direction on what to review.
Merge pull request #156 from JoshStrobl/master

Initial draft / write-up of Charm Review Process document

+1 LGTM  Thanks for the addition to the documentation!