KTX2 with Basis WebGL demos

Example webpages to render Basis Universal compressed textures, that are in KTX2 containers. All demos require WebAssembly and WebGL support.

• libktx and WebGL: uses libktx and its embedded Basisu transcoder compiled to .wasm and renders directly via WebGL.
• libktx and glTF 2.0: uses libktx and a glTF engine to load glTF files with KHR_texture_basisu for textures. TO BE IMPLEMENTED.
• transcodeImage with Pure JS KTX2 loader for three.js: transcodeImage is a BasisU transcoder method independent of .basis or any container format written in C++ and compiled to .wasm.
• transcodeImage with Pure JS .ktx2 parser and glTF 2.0: transcodeImage is a BasisU transcoder method independent of .basis or any container format written in C++ and compiled to .wasm. TO BE IMPLEMENTED.