Add Comments (#4)

* Preserve whitespace in posts

* Create comments handler

* Use comments handler

* Update paw

* Add comment components

* Style comments

* Remove unnecessary code from app

* Fix linter warning

* Add key to handle children (thx @javierbyte)

* Add toggling to the form

* Return all keys always

* Correct missing semicolons

* Restore redirect

* Render posts conditionally

* Set poll time to 1s

* Set post frequency to 2s

* Add polling to comments

* Correct typo in error logging

* Clear intervals and reduce polling

* Stops polling if it's being destroyed

* Update changelog