Tldr: Add top CLI tools from "Who needs a GUI?" article

[waldyrious]

@BryanLunduke's "Who needs a GUI? How to live in a Linux terminal." presents a list of the best CLI tools after attempting to go GUI-less for 30 days. These are probably good candidates for us to cover.

• [x] [mutt](https://en.wikipedia.org/wiki/Mutt_(email_client)) (common / linux)
• [x] [notmuch](https://notmuchmail.org/manpages/) (common / linux)
• [x] [alpine](https://www.washington.edu/alpine/mans.html) (common / linux)
• [x] [w3m](https://en.wikipedia.org/wiki/W3m) (common)
• [x] [nano](https://en.wikipedia.org/wiki/GNU_nano) (common)
• [x] [wordgrinder](http://cowlark.com/wordgrinder/index.html) (common / linux)
• [x] [cmus](https://en.wikipedia.org/wiki/Cmus) (common / linux)
• [x] [finch](https://developer.pidgin.im/wiki/Using%20Finch) (common / linux)
  
  
  
  • Guide to Using Finch - Terminal-Based Chat Client
  
  
  • Finch - Howto use Pidgin via Terminal Console
  
  
• [x] [hangups](https://github.com/tdryer/hangups) (common / linux)
• [x] [rainbowstream](http://rainbowstream.readthedocs.io/en/latest/#usage) (common / linux)
• [x] [rtv](https://github.com/michael-lazar/rtv) (common / linux)
• [x] [htop](http://hisham.hm/htop/) (linux)
• [x] [mc](https://en.wikipedia.org/wiki/Midnight_Commander) (common / linux)
• [x] [tmux](https://tmux.github.io/) (common)
• [x] [screen](https://en.wikipedia.org/wiki/GNU_Screen) (common)
• [x] [tpp](http://www.ngolde.de/tpp.html) (common / linux)

Most of these are interactive tools, which will present a challenge for documenting them in the tldr format, but if we can do vim and nano, we can do these as well :)

[sadboyzvone]

Hi, I've started to document some of these.
Should be done very soon.

[sbrl]

Update: mc and wordgrinder are now done, and there's a PR for mutt on the way :D

[luk3yx]

@waldyrious mutt and tpp seem to exist. Will this be updated?

[agnivade]

Thanks, updated.

[waldyrious]

Only 3 to go (notmuch, finch and rainbowstream)! Anyone up for checking the last boxes? :grinning:

[sbrl]

Just 1 left - so close!

[waldyrious]

@sbrl I've edited the opening comment to add two links to guides to using ´finch` that seem easier to parse than their official documentation — hopefully that helps whoever wants to work on that page!

[bl-ue]

Great jobs guys!

Thank you @qhyun2 for finishing this up!