Feature/website (#5)

* Add basic website
* Add website deploy action

website/gatsby-browser.js

@@ -0,0 +1,9 @@
+// Make scroll behavior of internal links smooth
+exports.onClientEntry = () => {
+  const SmoothScroll = require('smooth-scroll');
+  new SmoothScroll('a[href*="#"]', {
+    offset() {
+      return document.querySelector('#header').offsetHeight;
+    },
+  });
+};