[8.18] [DOCS][Reporting] Adds documentation of baseline screenshotting network policy to disallow external (elastic#233526) (elastic#233546)

# Backport

This will backport the following commits from `8.19` to `8.18`:
- [[DOCS][Reporting] Adds documentation of baseline screenshotting
network policy to disallow external
(elastic#233526)](elastic#233526)

<!--- Backport version: 10.0.1 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sorenlouv/backport)

<!--BACKPORT [{"author":{"name":"Nastasha
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Adds documentation of baseline screenshotting network policy to disallow
external (elastic#233526)\n\n## Summary\n\nUpdates the 8.18 and 8.19 docs to
include an example of a baseline\nscreenshotting network policy to
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Adds documentation of baseline screenshotting network policy to disallow
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BACKPORT-->

Author: nastasha-solomon

docs/settings/reporting-settings.asciidoc

@@ -241,6 +241,16 @@ xpack.screenshotting.networkPolicy:
   rules: [ { allow: true, host: "elastic.co", protocol: "https:" } ]
 -------------------------------------------------------
 
+Example of a baseline configuration for disallowing all requests to external paths:
+
+[source,yaml]
+-------------------------------------------------------
+xpack.screenshotting.networkPolicy:
+  rules: [ { allow: true, host: "localhost:5601", protocol: "http:" } ]
+-------------------------------------------------------
+
+NOTE: Typically, Chromium will connect to {kib} on a local interface, but this may be different based on the environment and specific <<reporting-kibana-server-settings>>.
+
 A final `allow` rule with no host or protocol allows all requests that are not explicitly denied:
 
 [source,yaml]