clean up post_new_route
simplify transition after successful edit
simplify custom validations in post_edit_controller
simplify custom validations in posts_new_controller and comments_new_controller
add handling of edit without changes to post_edit_controller's save method
prevent accumulation of event listeners in post_edit_controller's save method
add another user in seeds.rb
make setting of userId in posts_new_controller's save function depend on the current user
make setting of userId in comments_new_controller's save function depend on the current user
add author name to post index template
add computed property formattedDate to post.js and use it instead of createdAt in post index template
add display of formattedDate to post_in_list template