generate comment: content user_id post_id; add edit user btn
add edit page
add post "update"
add post and user dependency
generate comment model and controller

comment has dependency on post and user

post is limited to be displayed at most 300 character in post list,
so there is a "show" page for a post to display whole length post,
then user can have comments there

bug, user still cannot have comments
which means the comments won't be saved
and i havn't figured out