Always run --clear with watchexec

Signed-off-by: Oliver Davies <oliver@oliverdavies.uk>

modules/zsh/init.nix

@@ -1,3 +1,5 @@
+{ lib, ... }:
+
 {
   flake.modules.homeManager.base =
     { config, pkgs, ... }:
@@ -47,6 +49,10 @@
           command ${pkgs.ttyper}/bin/ttyper --language english1000 --words 50 "''${@}"
         }
 
+        watchexec() {
+          ${lib.getExe pkgs.watchexec} --clear "$@"
+        }
+
         weather() {
           curl "https://wttr.in/''$1"
         }