Avro IDL parsing

Parse Avro IDL specs into JSON protocols. Both synchronous and asynchronous modes are available:

const {assembleProtocol, assembleProtocolSync} = require('@avro/idl');

// Asynchronously:
assembleProtocol('path/to.avdl', (err, protocol) => {
  // protocol is an equivalent JSON representation of the IDL spec.
});

// Synchronously:
const protocol = assembleProtocolSync('path/to.avdl');