docs: Reword and improve the doc comment of removeUnnecessaryJoints…

… and its option `experimentalSameBoneCounts`

packages/three-vrm/src/VRMUtils/removeUnnecessaryJoints.ts

@@ -1,9 +1,13 @@
 import * as THREE from 'three';
 
 /**
- * Traverse given object and remove unnecessarily bound joints from every `THREE.SkinnedMesh`.
- * Some environments like mobile devices have a lower limit of bones and might be unable to perform mesh skinning, this function might resolve such an issue.
- * Also this function might greatly improve the performance of mesh skinning.
+ * Traverse the given object and remove unnecessarily bound joints from every `THREE.SkinnedMesh`.
+ *
+ * Some environments like mobile devices have a lower limit of bones
+ * and might be unable to perform mesh skinning with many bones.
+ * This function might resolve such an issue.
+ *
+ * Also, this function might significantly improve the performance of mesh skinning.
  *
  * @param root Root object that will be traversed
  */
@@ -13,9 +17,11 @@ export function removeUnnecessaryJoints(
     /**
      * If `true`, this function will compensate skeletons with dummy bones to keep the bone count same between skeletons.
      *
-     * This option might be effective for the shader compilation performance that matters to the initial rendering time,
+     * This option might be effective for the shader compilation performance that matters to the initial rendering time in WebGPURenderer,
      * especially when the model loaded has many materials and the dependent bone count is different between them.
      *
+     * Consider this parameter as experimental. We might modify or delete this API without notice in the future.
+     *
      * `false` by default.
      */
     experimentalSameBoneCounts?: boolean;