[v10.2.x] Docs: add missing alt text (#79539)

Docs: add missing alt text (#79537)

Added missing alt text

(cherry picked from commit cefd95f06e)

Co-authored-by: Isabel <76437239+imatwawana@users.noreply.github.com>

docs/sources/panels-visualizations/query-transform-data/_index.md

@@ -94,7 +94,7 @@ A panel's Query tab consists of the following elements:
 - **Expressions:** Uses the expression builder to create alert expressions.
   For more information about expressions, refer to [Use expressions to manipulate data][].
 
-{{< figure src="/static/img/docs/queries/query-editor-7-2.png" class="docs-image--no-shadow" max-width="1000px" >}}
+{{< figure src="/static/img/docs/queries/query-editor-7-2.png" class="docs-image--no-shadow" max-width="1000px" alt="The Query tab of the panel editor" >}}
 
 ## Add a query