[Bugfix] Expose port in Dockerfile and force IPv4 (#129)

* Exposes port on built image

* Forced IPv4

* Added current version to sidebar

lib/pinchflat_web/components/layouts/partials/sidebar.html.heex

@@ -57,6 +57,11 @@
             <.icon name="hero-currency-dollar" /> Donate
           </span>
         </li>
+        <li>
+          <span class="group relative flex items-center gap-2.5 px-4 py-2 text-sm">
+            v<%= Application.spec(:pinchflat)[:vsn] %>
+          </span>
+        </li>
       </ul>
     </nav>
   </section>