Update test to support groups of settings

Author: eliericha

testsuite/settings-doc/get-extension-settings.py

@@ -2,5 +2,9 @@
 import json
 
 pkg = json.load(sys.stdin)
-settings = pkg["contributes"]["configuration"][0]["properties"].keys()
+settings = []
+
+for group in pkg["contributes"]["configuration"]:
+    settings.extend(group["properties"].keys())
+
 print("\n".join(settings))