Generate Comment Model
Migrate Comment Model
Add Routing to Comment
Generate Comments Controller
Add Comment Form to articles/show
Add action comments#create
Add Comment Area into articles/show
Add Model Association comments to article
Typo comment_prams -> comment_params
Typo premit -> permit
Use Partial articles/show -> comments/_comment
Use Partial articles/show -> comments/_form
Add feature -> Destroy Comment
Fix Don't destroy comments when article deleted.