Add note about telemetry for CodeQL extension settings

docs/codeql/codeql-for-visual-studio-code/about-telemetry-in-codeql-for-visual-studio-code.rst

@@ -30,6 +30,7 @@ If you opt in, GitHub collects the following information related to the usage of
 - Randomly generated GUID that uniquely identifies a CodeQL extension installation. (Discarded before aggregation.)
 - IP address of the client sending the telemetry data. (Discarded before aggregation.)
 - Whether or not the ``codeQL.canary`` setting is enabled and set to ``true``.
+- Whether any :doc:`CodeQL extension settings <customizing-settings>` are configured.
 
 How long data is retained
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