[tracker: 1/2] And comment for updating nrl:lastModified when modifying ontologies

[Carlos Garnacho <carlosg src gnome org>]

commit dc76b3a9ef1bd50e765dc183ae65a2c439f8a391
Author: Pekka Vuorela <pekka vuorela jolla com>
Date:   Wed Dec 22 15:26:56 2021 +0200

    And comment for updating nrl:lastModified when modifying ontologies

 docs/reference/libtracker-sparql/defining-ontologies.md | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/docs/reference/libtracker-sparql/defining-ontologies.md 
b/docs/reference/libtracker-sparql/defining-ontologies.md
index 46b14428b..24746453d 100644
--- a/docs/reference/libtracker-sparql/defining-ontologies.md
+++ b/docs/reference/libtracker-sparql/defining-ontologies.md
@@ -394,3 +394,6 @@ possible incoherences (e.g. picking a single value if a property
 changes from multiple values to single value). After the manual
 data migration has been completed, the old classes and properties
 can be dropped.
+
+Once changes are made, the nrl:lastModified value should be updated
+so Tracker knows to reprocess the ontology.