Add note about requiring auto_rx v1.5.1

Author: darksidelemm

index.html

@@ -95,7 +95,9 @@ <h3>Radiosondes?</h3>
 
                 <h3>How do I receive?</h3>
                 Set up a receiver station using 
-                <a href="https://github.com/projecthorus/radiosonde_auto_rx/wiki">radiosonde_auto_rx</a>
+                <a href="https://github.com/projecthorus/radiosonde_auto_rx/wiki">radiosonde_auto_rx</a>.
+                <br/>
+                Note that you must be running at least v1.5.1 to show up on Sondehub v2!
 
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