Hide a column by clicking on `-` a lot.
Restore a column by clicking on it in the left column navigator.
notes:
 * keyboard navigation `1-9` seems to work weirdly.
  * if you minimize a column in the front, pressing `1` will take you
    to the _new_ first available column
  * if you minimize a column in the 4th position then it will
    absorb keypresses as if it is still there
 * the column heads show numbers, these are from CSS, therefore hiding
   a column makes the styles skip numbers making it appear as if they
   do not exist anywhere but the left navigation
 * lots of styles could probably be shaved out but i'm bad at everything
not tested columns:
 * any 'temporary' column (whatever those are)
 * columns with long titles and/or usernames
 * searches / trending / editable column titles
tested columns:
 * home
 * collections
 * notifications
 * messages / all messages
 * likes
 * mentions / all mentions
 * followers
 * activity
 * scheduled (seems good?)