fix: add clarifying comment

Author: dragontaek-lee

lib/helpers/model/applyStaticHooks.js

@@ -15,7 +15,7 @@ module.exports = function applyStaticHooks(model, hooks, statics) {
   };
 
   hooks = hooks.filter(hook => {
-    // If the custom static overwrites an existing middleware, don't apply
+    // If the custom static overwrites an existing query/aggregate middleware, don't apply
     // middleware to it by default. This avoids a potential backwards breaking
     // change with plugins like `mongoose-delete` that use statics to overwrite
     // built-in Mongoose functions.