chore: only track analytics on hexdocs.pm

mix.exs

@@ -25,7 +25,15 @@ defmodule Reactor.MixProject do
         before_closing_head_tag: fn type ->
           if type == :html do
             """
-            <script defer data-domain="ashhexdocs" src="https://plausible.io/js/script.js"></script>
+            <script>
+              if (location.hostname === "hexdocs.pm") {
+                var script = document.createElement("script");
+                script.src = "https://plausible.io/js/script.js";
+                script.setAttribute("defer", "defer")
+                script.setAttribute("data-domain", "ashhexdocs")
+                document.head.appendChild(script);
+              }
+            </script>
             """
           end
         end,