Add nodejs bindings

bindings/const_generator.py

bindings/nodejs/LICENSE

bindings/nodejs/README.md

bindings/nodejs/consts/arm.js

bindings/nodejs/consts/arm64.js

bindings/nodejs/consts/hexagon.js

bindings/nodejs/consts/index.js

bindings/nodejs/consts/keystone.js

bindings/nodejs/consts/mips.js

bindings/nodejs/consts/ppc.js

bindings/nodejs/consts/sparc.js

bindings/nodejs/consts/systemz.js

bindings/nodejs/consts/x86.js

bindings/nodejs/index.js

bindings/nodejs/package.json

bindings/nodejs/sample.js