Grid init

docs/_javascript/grid.js

@@ -0,0 +1,16 @@
+document.addEventListener('DOMContentLoaded', () => {
+
+  const $cells = getAll('.cell');
+
+  $cells.forEach(el => {
+    const parentWidth = el.parentElement.offsetWidth;
+    const percentage = el.offsetWidth / parentWidth * 100;
+    el.append(`${Math.round(percentage)}`);
+  });
+
+  // Functions
+  function getAll(selector) {
+    return Array.prototype.slice.call(document.querySelectorAll(selector), 0);
+  }
+
+});