Finish the per-language `examples/<lang>/` restructure by relocating the
WASM browser demo from bindings/wasm/examples/ to examples/wasm/.
* `examples/wasm/index.html` is the moved file; its WASM module import
becomes `../../bindings/wasm/pkg/wickra_wasm.js` so the demo still loads
the wasm-pack output without copying it.
* bindings/wasm/README.md, Quickstart-WASM.md, examples/README.md and the
root README "Languages" + project-layout block all point at the new
path. The serve command in the docs now says "serve the repository root
and open examples/wasm/index.html".
`bindings/wasm/examples/` is empty after the move; the now-empty
directory is removed.
kingchenc
d87005577e