title: Detect support for the @-ms-viewport rule in Edge
body: <p>Now that Microsoft has decided to move the @-ms-viewport rule in Edge behind an about:config flag, using javascript (not jquery) how do you determine if the user has that flag enabled (or is using an older version of Edge where it was still supported)?</p>
  
  <p>Thread about the withdrawal of the rule here <a href="https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/7970618/" rel="nofollow noreferrer">https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/7970618/</a></p>