I have added a foot.ini which preserves the color scheme that had been set up on xfce4-terminal (with the purple background and transparency), except using the Material color scheme for terminal fonts. The bright colors of the fonts look good on the purple, and are easier to read than the old font colors.
Other changes in this PR:
* Add foot to package lists; remove xfce4-terminal
* Autostart foot-server in Sway config
* Change default terminal in Sway config
* Change Waybar on-click actions to use footclient instead of xfce4-terminal
* Update cheatsheet, keyhint files
* Update Wofi, Thunar configs to use footclient instead of xfce4-terminal
* Add [swappy](https://github.com/jtheoof/swappy) for handling screenshots. It's a nice Flameshot-like tool that allows adding simple annotations (drawing circles, arrows, text, etc) to screenshots and can save to file or pass to the clipboard.
* Add keybindings for "snip", screenshot window, and screenshot current display.
* Add scripts for the screenshot window and screenshot current display functions.
* `packages-repository.txt` has also been alphabetically sorted to make it easier to work with.
