Fixes these problems:
* The `make` command for building the package simply called `makepkg` instead of `makepkg -s` which could also install missing dependencies with pacman
* The name of the package has been changed to tromjaro-theme-switcher but Makefile still used the old name theme-switcher, also the extension for Arch linux package is now `.tar.zst` instead of the previous `.tar.xz` - all of this meant that the `make install` command was not working properly
* `make clean` command didn't remove icons.zip and the proper linux package file which now ends in `.tar.zst` instead of the previous `.tar.xz`
