docs: fix some version_added values

Author: Nemental

plugins/modules/grafana_contact_point.py

@@ -24,7 +24,7 @@
 module: grafana_contact_point
 author:
   - Moritz Pötschk (@nemental)
-version_added: "1.9.0"
+version_added: "2.0.0"
 short_description: Manage Grafana Contact Points
 description:
   - Create/Update/Delete Grafana Contact Points via API.

plugins/modules/grafana_silence.py

@@ -23,7 +23,7 @@
 module: grafana_silence
 author:
   - flkhndlr (@flkhndlr)
-version_added: "1.8.0"
+version_added: "1.9.0"
 short_description: Manage Grafana Silences
 description:
   - Create/delete Grafana Silences through the Alertmanager Silence API.