bash: Add adjust-font function

Run this function, and then press -/+ to adjust the font suze on the
fly. Press q/Ctrl+C to quit.
mutt: add mutt/msmtp configs
i3: Start on the '🌐' desktop
i3: Start mutt with mod+shift+m, music with ..+p
mutt: Behave more like gmail

gi - go inbox
ga - go archive
A - Archive mail