Some work on Scripts

notable changes:
- rename `bt-connect` to `bt_connect`
- rename `music` to `media` and make it generic instead of checking
  Spotify
- make separate script to set background to a preset black image
- make all shebangs "#!/usr/bin/env sh"

Scripts/.local/scripts/st-scripts/link-grab.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env sh
 # From https://github.com/LukeSmithxyz/st
 
 urlregex="(((http|https|gopher|gemini|ftp|ftps|git)://|www\\.)[a-zA-Z0-9.]*[:;a-zA-Z0-9./+@$&%?$\#=_~-]*)|((magnet:\\?xt=urn:btih:)[a-zA-Z0-9]*)"

Scripts/.local/scripts/st-scripts/output-copy.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env sh
 # From https://github.com/LukeSmithxyz/st
 
 # By Jaywalker and Luke