Add 404 page

source/_pages/404.md

@@ -0,0 +1,22 @@
+---
+title: Page not found
+---
+
+{% block content %}
+Perhaps you were looking for one of these pages:
+
+- [Products and services](/pricing)
+- [Public speaking and workshops](/talks)
+- [My daily email list](/daily)
+- [The Beyond Blocks podcast](/podcast)
+
+If you were looking for something else, you can [search for it](/search).
+{% endblock %}
+
+{% block content_bottom %}
+  {% include 'daily-email-form.html.twig' with {
+    intro: 'Sign up and get daily emails about Drupal, PHP and software development.'
+  } %}
+
+  {% include 'about-me.html.twig' %}
+{% endblock %}