Add .gitignore and remove tracked __pycache__ and egg-info files

Agent-Logs-Url: https://github.com/jaraco/cssutils/sessions/ad467d75-777f-4968-9e2b-938f7219ee60

Co-authored-by: jaraco <308610+jaraco@users.noreply.github.com>

Author: Copilot

.gitignore

@@ -0,0 +1,23 @@
+*~
+.DS_Store
+.cache
+.eggs
+__pycache__
+build
+dist
+*.egg-info
+.tox
+.xprocess
+*.orig
+*.pyc
+node_modules
+.mypy_cache
+.pytest_cache
+.env
+.coverage
+pip-wheel-metadata
+.coverage.*
+.idea
+coverage.xml
+*.sublime-*
+.venv