doccheck: exclude dist/tools directory from group check

dist/tools/doccheck/check.sh

@@ -32,7 +32,7 @@ then
 fi
 
 exclude_filter() {
-    grep -v -e vendor -e examples -e tests
+    grep -v -e vendor -e examples -e tests -e "\<dist/tools\>"
 }
 
 # Check all groups are defined