message: docs: update how to remove a configuration item
  To remove a configuration item, `undefined` needs to be used as value.
  PR Close
diff: @@ -27,7 +27,7 @@ ng config --global cli.analyticsSharing.tracking UA-123456-12
  To turn off this feature, run the following command:
  <code-example language="sh">
  -ng config --global --remove cli.analyticsSharing
  +ng config --global cli.analyticsSharing undefined
  </code-example>
  ## Per user tracking
  