Fix terminal carousel on landing page of docs

This isn't perfect, but it is a step in the right direction. This fixes
the prev button not working at all and the next button having some
undesirable behavior.

This seems to work for the most part, but I noticed that if I leave this
open and go to a different tab in my browser, there's some strange
behavior when I come back to the landing page: there are multiple
outputs playing at once. This is similar to the current behavior, where
clicking the next button multiple times does the same thing.
Try $VISUAL and $EDITOR for config['editor']

On UNIX derivates they expand to the default or preferred editor and avoid
unnecessary first time edits of the config file.
Merge pull request #175 from jonjonsonjr/master

Fix terminal carousel on landing page of docs
Merge pull request #178 from matze/use-env-editor

Try $VISUAL and $EDITOR for config['editor']
Update recipies.rst with correct notepad++ options.
Typo fix

A quick spelling correction and I swapped the position of 2 words for clarity.
Merge pull request #180 from mason-bially/master

Update recipies.rst with correct notepad++ options.
Merge pull request #181 from jenmontes/patch-1

Typo fix
Move 3L into vendors dir
Use PyXDG to determine XDG_CONFIG_HOME