doc: update the description of the return type for options.filter

Author: kylo5aby

doc/api/fs.md

@@ -1049,7 +1049,7 @@ changes:
     that resolves to `true` or `false` **Default:** `undefined`.
     * `src` {string} source path to copy.
     * `dest` {string} destination path to copy to.
-    * Returns: {boolean|Promise}
+    * Returns: `Promise` or the type that is coercible to `boolean`.
   * `force` {boolean} overwrite existing file or directory. The copy
     operation will ignore errors if you set this to false and the destination
     exists. Use the `errorOnExist` option to change this behavior.
@@ -2455,7 +2455,7 @@ changes:
     that resolves to `true` or `false` **Default:** `undefined`.
     * `src` {string} source path to copy.
     * `dest` {string} destination path to copy to.
-    * Returns: {boolean|Promise}
+    * Returns: `Promise` or the type that is coercible to `boolean`.
   * `force` {boolean} overwrite existing file or directory. The copy
     operation will ignore errors if you set this to false and the destination
     exists. Use the `errorOnExist` option to change this behavior.
@@ -5447,7 +5447,7 @@ changes:
     all of its contents will be skipped as well. **Default:** `undefined`
     * `src` {string} source path to copy.
     * `dest` {string} destination path to copy to.
-    * Returns: {boolean}
+    * Returns: the type that is coercible to `boolean`.
   * `force` {boolean} overwrite existing file or directory. The copy
     operation will ignore errors if you set this to false and the destination
     exists. Use the `errorOnExist` option to change this behavior.