Add .gitignore to exclude venv and other files

.gitignore

@@ -0,0 +1,20 @@
+# Virtualenv
+venv/
+/venv/
+
+# Python bytecode and cache
+__pycache__/
+*.py[cod]
+*$py.class
+
+# Django specific
+*.log
+db.sqlite3
+db.sqlite3-journal
+local_settings.py # 如果你打算用一个本地独有的设置文件
+
+# IDE / Editor specific (optional, but good practice)
+.vscode/
+.idea/
+*.swp
+*~