chore: add .dockerignore to exclude common development and build artifacts from Docker builds.

.dockerignore

@@ -0,0 +1,24 @@
+**/node_modules
+**/dist
+.git
+.gitignore
+.env
+__pycache__
+*.pyc
+*.pyo
+*.pyd
+.Python
+env/
+venv/
+pip-log.txt
+pip-delete-this-directory.txt
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.log
+.pytest_cache/
+screenshots/