A new option `--parallel` (or `-P` for short) is introduced to enable parallel execution of `adstex` to speed things up. This new option is *not* enabled by default. When `--parallel` is set, `adstex` will use 8 threads to look up the references. One can adjust the number of threads by setting `--threads=x`.
Thanks to dwijn for suggesting and implementing this new feature.
**Full Changelog**: https://github.com/yymao/adstex/compare/v0.4.0...v0.5.0