Add hotjar

Author: josix

src/components/seo.js

@@ -103,6 +103,18 @@ const SEO = ({ description, lang, meta, title }) => {
           }
         `}
       </style>
+      <!-- Hotjar Tracking Code for josix.tw -->
+      <script>
+          {`(function(h,o,t,j,a,r){
+              h.hj=h.hj||function(){(h.hj.q=h.hj.q||[]).push(arguments)};
+              h._hjSettings={hjid:2539800,hjsv:6};
+              a=o.getElementsByTagName('head')[0];
+              r=o.createElement('script');r.async=1;
+              r.src=t+h._hjSettings.hjid+j+h._hjSettings.hjsv;
+              a.appendChild(r);
+          })(window,document,'https://static.hotjar.com/c/hotjar-','.js?sv=');
+          `}
+      </script>
       <script async src="https://cdn.volument.com/v1/volument.js" onload={`volument('${process.env.GATSBY_VOLUMENT_ID}')`}></script>
 
     </Helmet>