message: Update RELEASE_NOTES for 1.9.21
diff: @@ -7,8 +7,19 @@ A new header is inserted each time a *tag* is created.
  - engine: Add new `Renderer::renderStandaloneView()` API.
  +## v1.9.22
  +
  ## v1.9.21
  +- JavaScript: add missing TextureSampler bindings.
  +- Metal: Fix texture swizzling crash with older Nvidia GPUs.
  +- Vulkan: fix image layout validation error on Android.
  +- android: fix MSAA w/ multisampled_render_to_texture on Mali.
  +- engine: better anisotropic filtering with various drivers.
  +- gltfio: Use BufferObject API, simplify MorphHelper.
  +- gltfio: honor stride in normalizeSkinningWeights.
  +- samples: Add web component demo.
  +
  ## v1.9.20
  - Android: Fix VSM.
  