please npm-publish release binaries!

[devdoomari3]

please publish release binaries in npm --- something like protoc-bin will do.

it'll simplify initial on-boarding for JS developers with grpc projects.

(putting protoc file inside node_modules/.bin folder will do)

thank you!

[dibenede]

This project doesn't release protoc itself (though this was filed at a time when both projects were 1 repo). We could potentially add the protoc-gen-js plugin to the npm package.