010: Improved Active Storage docs, a new has_secure_token callback with Dave Kimura

Dave Kimura of Drifting Ruby fame joins me to discuss the importance of Ruby on Rails documents. We talk specifically about improved documentation around Active Storage and Active Record encryption, then dive into the new callback for when has_secure_token is triggered.

Improved Active Storage docs (This PR was updated)
Improved Active Record Encryption docs
Eagerly cast serialized query attributes
A callback for has_secure_token