Added checks to make sure the specified track exists

Added precondition checks to validate input files and paths to return more informative error messages as per #2

node_modules/prompts/dist/util/strip.js

@@ -0,0 +1,7 @@
+'use strict';
+
+module.exports = str => {
+  const pattern = ['[\\u001B\\u009B][[\\]()#;?]*(?:(?:(?:[a-zA-Z\\d]*(?:;[a-zA-Z\\d]*)*)?\\u0007)', '(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PRZcf-ntqry=><~]))'].join('|');
+  const RGX = new RegExp(pattern, 'g');
+  return typeof str === 'string' ? str.replace(RGX, '') : str;
+};