Fix collapsing page widths

Fix inconsistent page widths on some pages such as blog and talks, by
adding a width (i.e. a `w-full` class) as well as a maximum width.

web/themes/custom/opdavies/templates/layout/page.html.twig

@@ -78,7 +78,12 @@
         </div>
       </div>
     </div>
-    <div class="{{ is_front ? 'max-w-5xl' : 'max-w-3xl' }} mx-auto p-4 space-y-8">
+    <div
+      class="
+        w-full mx-auto p-4 space-y-8
+        {{ is_front ? 'max-w-5xl' : 'max-w-3xl' }}
+      "
+    >
 
       {{ page.secondary_menu }}