Fix typo in conf.py

The `subset` and `defect` tags had their descriptions swapped with one another. Now they're all good :)

Author: felix91gr

src/conf.py

@@ -102,8 +102,8 @@
     dict(name="undefined-behavior", description="Numerics-related guideline"),
     dict(name="stack-overflow", description="Stack-overflow-related guideline"),
 
-    dict(name="defect", description="Guideline associated with the language-subset profile"),
-    dict(name="subset", description="Guideline associated with the defect-prevention profile"),
+    dict(name="subset", description="Guideline associated with the language-subset profile"),
+    dict(name="defect", description="Guideline associated with the defect-prevention profile"),
 ]
 
 needs_categories = [