#3 Add window tiling shortcuts

JWM can use hotkeys to tile or otherwise arrange and maximize windows to specific portions of the desktop.

I also changed some hotkeys in another commit. (You don't have to include that one.)

Thanks for the PR.

The additions mostly looks ok to me. One thing though, I think Super+ keyboard shortcuts can live together with Ctrl+Alt+ shortcuts. e.g. Both Super+T and Ctrl+Alt+T can be there. As far as I know, it wouldn't cause issues, but feel free to test. I added Ctrl+Alt+T because it was a standard on other DEs and some might be used to that. I'm not too sure about Ctrl+Alt+E though. Are you sure this won't conflict with some other keyboard shortcut?

Same way "Super key" and "Ctrl+Escape" can both stay. (Readme can say Super key or Ctrl+Escape.) This way whichever user likes to use can be used.

Other points would be:

• Please make the indentation match the rest of the code (.jwmrc).
• Please keep the file manager to thunar, and not exec:pcmanfm --no-desktop. I'm thinking of implementing a templating system for this config. Then customization would be more independent than the defaults. But until this is done, uniformity should be maintained so that it can be replaced with template placeholders.
• Please fix Super+E or Super+E. If above point is considered, should be something like Super+E or Ctrl+Alt+E.