Add Grafana Free as supporting Enterprise features (grafana#67568)

Per https://docs.google.com/document/d/14aOVLPq0FNqQKN4axTTEvjraY_OafhiDM_2NYSHF33A/edit#heading=h.lo4c6e71q7vo Grafana Cloud Free will include all the features of Grafana Advanced in Q2

Author: rgnvldr

docs/sources/introduction/grafana-enterprise.md

@@ -19,7 +19,7 @@ To learn more about Grafana Enterprise, refer to [our product page](https://graf
 
 ## Enterprise features in Grafana Cloud
 
-Many Grafana Enterprise features are also available in [Grafana Cloud](/docs/grafana-cloud) Pro and Advanced accounts. For details, refer to [the Grafana Cloud features table](https://grafana.com/pricing/#featuresTable).
+Many Grafana Enterprise features are also available in [Grafana Cloud](/docs/grafana-cloud) Free, Pro, and Advanced accounts. For details, refer to [the Grafana Cloud features table](https://grafana.com/pricing/#featuresTable).
 
 ## Authentication