Updated config file for alacritty 0.6.
Removed a lot of the commenting cruft still stuck in the original
configuration file.
A sample commented version of the config file can nowadays be found at
`/usr/share/doc/alacritty/alacritty.yml`.
Removed autostarting of new tmux sessions for each new alacritty window.
The auto-closing and deluge of unnamed sessions did not help keep any
kind of organizational scheme, and lead to actual named sessions (like
notes, and dot) to perish under the mountain of sessions.
Updated the alacritty settings file to follow the correct format for
newer alacritty versions by conforming it to the setting file template
with choice differences for my setup.
