Add .gitignore file.

.gitignore

+# generic files to ignore
+.*
+
+# python temp paths
+__pycache__/
+*.py[cod]
+
+# editors
+*~
+*.swp
+*.swo
+*#
+
+# ms-windows
+Thumbs.db
+ehthumbs.db
+Desktop.ini
+
+# commonly used paths in blender
+/blender.bin
+/user-config.py
+