website: add sidebar structure

contents/_components/QuestionList.js

@@ -0,0 +1,42 @@
+import React from 'react';
+
+import QuestionGroups from './QuestionGroups.json';
+
+export default function QuestionList() {
+  return (
+    <div className="padding-vert--lg">
+      {Object.entries(QuestionGroups).map(
+        ([sectionTitle, questions], index) => (
+          <div className="margin-bottom--lg" key={sectionTitle}>
+            <h4>Week {index + 5}</h4>
+            <table>
+              <thead>
+                <tr>
+                  <th>Problem</th>
+                  <th>Difficulty</th>
+                  <th>Duration</th>
+                </tr>
+              </thead>
+              <tbody>
+                {questions.map((question) => (
+                  <tr key={question.slug}>
+                    <td>
+                      <a
+                        href={question.url}
+                        target="_blank"
+                        rel="noopener noreferer">
+                        {question.title}
+                      </a>
+                    </td>
+                    <td>{question.difficulty}</td>
+                    <td>{question.duration} mins</td>
+                  </tr>
+                ))}
+              </tbody>
+            </table>
+          </div>
+        ),
+      )}
+    </div>
+  );
+}