DTX XA to WAV conversion library

Usage example:

let convert = require('xa-dtx');

convert('file.xa').then(wav => {
  console.log('XA file converted to buffer', wav);
});

convert('file.xa', 'file.wav').then(() => {
  console.log('XA file converted to WAV file');
});

let xaBuffer = fs.readFileSync('file.xa')
convert(xaBuffer).then(wav => {
  console.log('XA buffer converted to buffer', wav);
});