Changed wagtail.readthedocs.org to docs.wagtail.io consistently

wagtail/project_template/home/templates/home/home_page.html

@@ -7,5 +7,5 @@
 
     <p>You can access the admin interface <a href="{% templatetag openblock %} url 'wagtailadmin_home' {% templatetag closeblock %}">here</a> (make sure you have run "./manage.py createsuperuser" in the console first).
 
-    <p>If you haven't already given the documentation a read, head over to <a href="http://wagtail.readthedocs.org/">http://wagtail.readthedocs.org</a> to start building on Wagtail</p>
+    <p>If you haven't already given the documentation a read, head over to <a href="http://docs.wagtail.io/">http://docs.wagtail.io</a> to start building on Wagtail</p>
 {% templatetag openblock %} endblock {% templatetag closeblock %}