docs/tests: update UI tests reporting

docs/tests/ui-tests.md

@@ -76,8 +76,18 @@ pytest tests/device_tests --ui=record --ui-check-missing
 
 ## Reports
 
+### Tests
+
 Each `--ui=test` creates a clear report which tests passed and which failed.
-The index file is stored in `tests/ui_tests/reports/index.html`, but for an ease of use
+The index file is stored in `tests/ui_tests/reporting/reports/test/index.html`, but for an ease of use
 you will find a link at the end of the pytest summary.
 
 On CI this report is published as an artifact.
+
+### Master diff
+
+In the ui tests folder you will also find a Python script `report_master_diff.py`, which
+creates a report where you find which tests were altered, added, or removed relative to
+master. This useful for Pull Requests.
+
+This report is available as an artifact on CI as well.