[pypi] add pdm.lock (#10)

Author: zbowling

.gitignore

@@ -56,7 +56,7 @@ ipython_config.py
 
 # pdm
 #   Similar to Pipfile.lock, it is generally recommended to include pdm.lock in version control.
-pdm.lock
+# pdm.lock
 #   pdm stores project-wide configurations in .pdm.toml, but it is recommended to not include it
 #   in version control.
 #   https://pdm-project.org/#use-with-ide