Add a .gitignore.

.gitignore

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..a6135e8
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,38 @@
+build/
+__pycache__
+*.py[cod]
+*~
+@*
+/build
+/env
+docs/build/
+*.iml
+/out/
+.venv/
+.mypy_cache/
+.incremental_checker_cache.json
+.cache
+dmypy.json
+.dmypy.json
+
+# Packages
+*.egg
+*.egg-info
+*.eggs
+
+# IDEs
+.idea
+*.swp
+.vscode
+
+# Operating Systems
+.DS_Store
+
+# Coverage Files
+htmlcov
+.coverage*
+
+# pytest cache
+.pytest_cache/
+
+.tox