Add wildcard widget examples guide (#28854)

Co-authored-by: amymzhou <[email protected]>

Author: estherk15

content/en/dashboards/guide/_index.md

@@ -33,6 +33,7 @@ cascade:
     {{< nextlink href="/dashboards/guide/version_history" >}}Version History{{< /nextlink >}}
     {{< nextlink href="/dashboards/guide/graphing_json/" >}}Graphing with JSON{{< /nextlink >}}
     {{< nextlink href="/dashboards/guide/using_vega_lite_in_wildcard_widgets/" >}}Using Vega-Lite with Wildcard Widgets in Datadog{{< /nextlink >}}
+    {{< nextlink href="/dashboards/guide/wildcard_examples" >}}Wildcard widget Examples{{< /nextlink >}}
     {{< nextlink href="/dashboards/guide/graphing_json/" >}}Graphing with JSON
     {{< /nextlink >}}
     {{< nextlink href="/dashboards/guide/tv_mode" >}}Using TV mode for Dashboards