Doom Emacs w/ Personal Config

- Update flake.lock
- Add doom emacs nix module to flake
- Change default editor to doom emacs
- Move xdg configuration to a separate file
- Change user home filepaths to use `~`
- Install doom emacs by default
- Add personal doom emacs configuration

system/gui/dwm.nix

@@ -10,7 +10,7 @@
   services.xserver.windowManager.dwm = {
     enable = true;
     package = pkgs.dwm.overrideAttrs {
-      src = /home/sravan/.config/dwm-flexipatch;
+      src = ~/.config/dwm-flexipatch;
       buildInputs = with pkgs; [
         xorg.libX11.dev
         xorg.libXinerama