Update mercure.rst

Co-authored-by: Wouter J <[email protected]>

Author: dunglas

mercure.rst

@@ -77,9 +77,10 @@ On Linux and Mac, run the following command to start it:
 
 On Windows run:
 
+.. rst-class: command-windows
 .. code-block:: terminal
 
-    $env:SERVER_NAME=':3000'; $env:MERCURE_PUBLISHER_JWT_KEY='!ChangeMe!'; $env:MERCURE_SUBSCRIBER_JWT_KEY='!ChangeMe!'; .\mercure.exe run -config Caddyfile.dev
+    > $env:SERVER_NAME=':3000'; $env:MERCURE_PUBLISHER_JWT_KEY='!ChangeMe!'; $env:MERCURE_SUBSCRIBER_JWT_KEY='!ChangeMe!'; .\mercure.exe run -config Caddyfile.dev
 
 .. note::