adjustSource = (initialSource, exportsDir, outputDir) => {
  const initialSourcePath = path.resolve(exportsDir, initialSource);
  const adjustedSource = path.relative(outputDir, initialSourcePath);
  return adjustedSource.startsWith('.') ? adjustedSource : `./${adjustedSource}`;
}
Adjusts the source by updating the relative path value

@param {string} initialSource Example: `import sth from source;`
@param {string} exportsDir
@param {string} outputDir
@returns {string}