Update index.html

Author: JustDeveloper1

index.html

@@ -60,7 +60,7 @@ <h3>Grab your own sweet-looking <span>.is-a.dev</span> subdomain.</h3>
                 src="//cdn.carbonads.com/carbon.js?serve=CW7DE2JU&placement=is-adev&format=cover"
                 id="_carbonads_js"></script>
 
-            <h2>Check Subdomain Availability</h2>
+            <h2>Check Subdomain Availability<small><a target="_blank" href="https://all.is-a.dev/">List of all subdomains</a></small></h2>
             <div class="search-cntnr">
                 <input id="search-domain" disabled type="text">
             </div>