message: Update README.md
  Add a note wrt gltfpack simplification support.
diff: @@ -288,7 +288,7 @@ You can then run the resulting command-line binary like this (run it without arg
  gltfpack -i scene.gltf -o scene.glb
  ```
  -gltfpack substantially changes the glTF data by optimizing the meshes for vertex fetch and transform cache, quantizing the geometry to reduce the memory consumption and size, merging meshes to reduce the draw call count, quantizing and resampling animations to reduce animation size and simplify playback, and pruning the node tree by removing or collapsing redundant nodes.
  +gltfpack substantially changes the glTF data by optimizing the meshes for vertex fetch and transform cache, quantizing the geometry to reduce the memory consumption and size, merging meshes to reduce the draw call count, quantizing and resampling animations to reduce animation size and simplify playback, and pruning the node tree by removing or collapsing redundant nodes. It will also simplify the meshes when requested to do so.
  gltfpack can produce two types of output files:
  