[release-11.5.3] Alerting docs: dynamic label changes (#101866)

Alerting docs: dynamic label changes (#101781)

(cherry picked from commit 23ccd2be95)

Co-authored-by: Pepe Cano <825430+ppcano@users.noreply.github.com>

docs/sources/shared/alerts/note-dynamic-labels.md

@@ -0,0 +1,14 @@
+---
+labels:
+  products:
+    - oss
+title: 'Note Dynamic labels'
+---
+
+{{% admonition type="note" %}}
+
+An alert instance is uniquely identified by its set of labels.
+
+- Avoid displaying query values in labels, as this can create numerous alert instances—one for each distinct label set. Instead, use annotations for query values.
+- If a templated label's value changes, it maps to a different alert instance, and the previous instance transitions to the `No data` state when its label value is no longer present.
+  {{% /admonition %}}