TODO

   1 - [ ] remove dependency on http-client
   2 - [ ] optional text wrap
   3 - [ ] write
   4 - [ ] caching (use cache by default, unless explicitly asked for update)
   5   - [x] value --> cache
   6   - [x] value <-- cache
   7     requires: commands
   8 - [ ] timeline limits
   9 - [ ] feed set operations (perhaps better done externally?)
  10 - [ ] timeline as a result of a query (feed set op + filter expressions)
  11 - [ ] named timelines
  12 - [ ] config files
  13 - [ ] parse "following" from feed
  14   - following = <nick> <uri>
  15 - [ ] parse mentions:
  16   - @<source.nick source.url> | @<source.url>
  17 - [ ] highlight mentions
  18 - [ ] filter on mentions
  19 - [ ] highlight hashtags
  20 - [ ] filter on hashtags
  21 - [ ] hashtags as channels? initial hashtag special?
  22 - [ ] query language
  23 - [ ] console logger colors by level ('error)
  24 - [ ] file logger ('debug)
  25 - [ ] commands:
  26   - r | read
  27     - see timeline ops above
  28   - w | write
  29     - arg or stdin
  30     - nick expand to URI
  31   - q | query
  32     - see timeline ops above
  33     - see hashtag and channels above
  34   - d | download
  35   - u | upload
  36     - calls user-configured command to upload user's own feed file to their server
  37   Looks like a better CLI parser than "racket/cmdline":
  38   https://docs.racket-lang.org/natural-cli/