Outdated links in README.md

I think the link to "glTF Compressor" just above Credits and that to the "live demo" given under WebApp should be changed to https://github.khronos.org/glTF-Compressor-Release/. And "A live demo" should be changed to "The live version" since it is now released, as far as I know.

I'll be happy to update the README if someone confirms the links should be fixed. Is a direct edit okay or do you want a PR?

Open README.md and locate the glTF Compressor link above Credits and the live demo link under WebApp. Update both links to https://github.khronos.org/glTF-Compressor-Release/ and change “A live demo” to “The live version.” Done means both references and the wording match the requested released destination.

Written by the indexing model from the issue text.