message: gltfpack: Update README
  Add a note about -cc and gzip.
diff: @@ -24,7 +24,9 @@ By default gltfpack outputs regular `.glb`/`.gltf` files that have been optimize
  When using `-c` option, gltfpack outputs compressed `.glb`/`.gltf` files that use meshoptimizer codecs to reduce the download size further. Loading these files requires extending GLTF loaders with support for `MESHOPT_compression` extension; [demo/GLTFLoader.js](https://github.com/zeux/meshoptimizer/blob/master/demo/GLTFLoader.js) contains a custom version of three.js loader that can be used to load them.
  -Additionally, gltfpack can compress textures using Basis Universal format, either storing .basis images directly (`-tb` flag, supported by three.js) or using KTX2 container (`-tc` flag, requires support for `KHR_image_ktx2`). Compression is performed using `basisu` executable.
  +For better compression, you can use `-cc` option which applies additional compression; additionally make sure that your content delivery method is configured to use deflate (gzip) - meshoptimizer codecs are designed to produce output that can be compressed further with general purpose compressors.
  +
  +gltfpack can also compress textures using Basis Universal format, either storing .basis images directly (`-tb` flag, supported by three.js) or using KTX2 container (`-tc` flag, requires support for `KHR_image_ktx2`). Compression is performed using `basisu` executable and is thus only available in native builds.
  When using compressed files, [js/meshopt_decoder.js](https://github.com/zeux/meshoptimizer/blob/master/js/meshopt_decoder.js) needs to be loaded to provide the WebAssembly decoder module like this:
  