move options back out to their config files, improve documentation

modules/features/services/easyeffects.nix

@@ -1,4 +1,8 @@
 { inputs, self, ... }: {
+  flake.homeModules.audioOptions = { lib, ...}: {
+    options.features.services.easyeffects.enable = lib.mkEnableOption "Easy Effects";
+  };
+
   flake.homeModules.audio = { pkgs, config, lib, ...}: {
     config = lib.mkIf (config.features.services.easyeffects.enable) {
       services.easyeffects.enable = true;