Add style components for zebra-tables and responsive-tables.

assets/js/tables.js

@@ -0,0 +1,28 @@
+/**
+ * @file
+ * A JavaScript file for responsive tables.
+ */
+
+(function () {
+
+  'use strict';
+
+  const tables = document.querySelectorAll('.responsive-table');
+
+  tables.forEach(function (table) {
+    const headers = table.querySelectorAll('th');
+    const rows = table.querySelectorAll('tr:has(td)');
+
+    rows.forEach(function (row) {
+      const cells = row.querySelectorAll('td');
+      cells.forEach(function (cell, i) {
+        cell.setAttribute('role','cell');
+        if (headers[i].innerText) {
+          cell.setAttribute('aria-label', headers[i].innerText);
+        }
+      });
+    });
+  });
+
+
+})();