RELEASE.md

This document details my release process. Maybe someday I'll automate it.

1. Commit updated versions of CHANGES.md and setup.py
2. Make sure the directory is clean: git status shows nothing
3. Create a new virtual environment and install twine and setuptools
4. Run python setup.py sdist
5. Upload to PyPI with twine upload dist/pdftotext-X.X.X.tar.gz
6. Tag the release on GitHub