add python-debugger extension to devcontainer configuration

Author: rongxin-liu

devcontainer.json

@@ -16,6 +16,7 @@
                 "/opt/cs50/extensions/ddb50-2.0.0.vsix",
                 "/opt/cs50/extensions/phpliteadmin-0.0.1.vsix",
                 "/opt/cs50/extensions/style50-0.0.1.vsix",
+                "/opt/cs50/extensions/python-debugger.vsix",
                 "/opt/cs50/extensions/ms-python-insiders.vsix",
                 "cs50.extension-uninstaller",
                 "inferrinizzard.prettier-sql-vscode",