Centered and smaller text for the documentation section

Signed-off-by: Benoit Donneaux <benoit@leastauthority.com>

src/index.html

@@ -19,23 +19,26 @@ documentation_list:
   - image_path: /assets/images/overview.svg
     alt: "overview"
     title: "Overview"
-    excerpt: '
-      This [one-page summary](https://tahoe-lafs.readthedocs.io/en/latest/about-tahoe.html) explains the unique properties of this system
-    '
+    excerpt: >-
+      <center>
+      <a href="https://tahoe-lafs.readthedocs.io/en/latest/about-tahoe.html">One-page summary</a>
+      </center>
   - image_path: /assets/images/manual.svg
     alt: "manual"
     title: "Manual"
-    excerpt: '<ul>
-      <li><a href="https://tahoe-lafs.readthedocs.io/en/latest/Installation/install-tahoe.html">Installation Instructions</a></li>
-      <li><a href="http://tahoe-lafs.readthedocs.org/">Tahoe-LAFS Manual</a></li>
-    </ul>'
+    excerpt: >-
+      <center>
+      <p><a href="https://tahoe-lafs.readthedocs.io/en/latest/Installation/install-tahoe.html">Installation Instructions</a></p>
+      <p><a href="http://tahoe-lafs.readthedocs.org/">Tahoe-LAFS Manual</a></p>
+      </center>
   - image_path: /assets/images/wiki.svg
     alt: "wiki"
     title: "Wiki"
-    excerpt: '<ul>
-      <li><a href="https://tahoe-lafs.org/trac/tahoe-lafs/wiki/Doc">Index of docs</a></li>
-      <li><a href="https://tahoe-lafs.org/trac/tahoe-lafs/wiki/FAQ">Frequently Asked Questions</a></li>
-    </ul>'
+    excerpt: >-
+      <center>
+      <p><a href="https://tahoe-lafs.org/trac/tahoe-lafs/wiki/Doc">Index of docs</a></p>
+      <p><a href="https://tahoe-lafs.org/trac/tahoe-lafs/wiki/FAQ">Frequently Asked Questions</a></p>
+      </center>
 contribute:
   - title: "Contribute"
     excerpt: ""