load MathJax async

Author: mojavelinux

src/partials/footer-scripts.hbs

@@ -18,7 +18,7 @@ MathJax.Hub.Register.StartupHook("AsciiMath Jax Ready", function () {
   })
 })
 </script>
-<script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.9/MathJax.js?config=TeX-MML-AM_HTMLorMML"></script>
+<script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.9/MathJax.js?config=TeX-MML-AM_HTMLorMML"></script>
 {{/unless}}
 {{/with}}
 {{#if env.ALGOLIA_API_KEY}}