rofi: Remove unused modes

It turns out that 'window' (as of this writing) does not work very well
when trying to use it as an alt-tab replacement. It's simply easier to
just use the functionality provided by your window manager instead.

I have never used rofi's 'run' feature, since any time I'd need to run
a command I'd just do it from a terminal, which also lets me see any
output from that program as well.

rofi/.config/rofi/config.rasi

@@ -1,5 +1,5 @@
 configuration {
-  modi: "window,run,drun";
+  modi: "drun";
   font: "Hack 12";
   show-icons: true;
   bw: 0;