Added vim-like navigation (#11)

themes/alejandro-angulo/layouts/partials/footer.html

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+<script src="/js/keynav.js"></script>

themes/alejandro-angulo/static/js/keynav.js

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+/*
+ * Adds vim-like keyboard navigation.
+ *
+ * Currently supports:
+ * - j (scroll down)
+ * - k (scroll up)
+ * - gg (scroll to top)
+ * - G (scroll to bottom)
+ */
+
+const scroll_vertical = 100;
+const scroll_behavior = "smooth";
+let last_key = null;
+
+document.addEventListener("keydown", (e) => {
+  console.log(e);
+
+  let scroll_factor = 1;
+
+  if (e.key === "k") {
+    scroll_factor *= -1;
+  }
+
+  switch (e.key) {
+    case "j":
+    case "k":
+      window.scrollBy({
+        top: scroll_factor * scroll_vertical,
+        behavior: scroll_behavior,
+      });
+      break;
+
+    case "g":
+      if (last_key === "g") {
+        window.scroll(0, 0);
+      }
+      break;
+
+    case "G":
+      window.scroll(0, document.body.scrollHeight);
+      break;
+  }
+
+  last_key = e.key;
+});