Emacs: configure auto-config

Cc: Ratheesh S <ratheeshreddy@gmail.com>
Tested-by: Ratheesh S <ratheeshreddy@gmail.com>
Signed-off-by: Ratheesh S <ratheeshreddy@gmail.com>
Emacs: Add customizations to dark theme

Customize based on the emacs theme editor.

Tested-by: Ratheesh S <ratheeshreddy@gmail.com>
Signed-off-by: Ratheesh S <ratheeshreddy@gmail.com>