SDK: warning shown when building WASM locally

[ok300]

The instructions for the JS bindings include:

pubky-core/pubky-sdk/bindings/js/README.md

Lines 23 to 26 in 0ec564d

	npm install # grab JS deps once
	npm run build # compile wasm + patch bundle
	npm run testnet # start local DHT + relay + homeserver (in another terminal)
	npm run test # run tape tests against the testnet + browser harness

However the 2nd command shows the following licensing warning:

npm run build

[INFO]: ⬇️  Installing wasm-bindgen...
[INFO]: License key is set in Cargo.toml but no LICENSE file(s) were found; Please add the LICENSE file(s) to your project directory
[INFO]: ✨   Done in 27.10s
[INFO]: 📦   Your wasm pkg is ready to publish at /home/x/Projects/pubky-core/pubky-sdk/bindings/js/pkg/nodejs.

Please create a LICENSE file to address this.