How do I automatically generate a migration?

rails generate migration create_posts title: source:text author:integer  
How do I automatically generate a migration with timestamps

rails generate migration create_comments user_id:integer post_id:integer content:text :timestamps

This gives an extra colon after the timestamp generation, so it's not quiet right.
How do I create associations in rails?

We have some associations!

Ryan told me I don't need to have a has_many through relationship because nothing in my app demands that a user know about the posts that it has commented on. There's to reason why User.posts should mean posts the user has commented on.
Added posts to front page and individual posts view

You can now see a post. Wohoo!
You can now see comments on posts

I copied my view as-is, mostly, from my old sinatra project
https://github.com/tararoys/HackerNewsCRUDexample/blob/master/app/views/post.erb

Notably broken  still are user profiles and the new comment link
How do I a create comments page to my app with rails?

Like this!
Concepts learned:
resources are like rooms
nested resources are like saying that this box of things is only availible in this room
restricted routes are like saying let's only build the railroad lines we need when we need them.