Move all pages into their own directory

There are a lot of pages. It seems like a good idea to keep them in one place,
so they don’t get mixed up with partials and layouts.

app/templates/views/api-keys.html

@@ -0,0 +1,20 @@
+{% extends "admin_template.html" %}
+
+{% block page_title %}
+GOV.UK Notify | API keys and documentation
+{% endblock %}
+
+{% block content %}
+
+<div class="grid-row">
+	<div class="column-two-thirds">
+		<h1 class="heading-xlarge">API keys and documentation</h1>
+
+		<p>Here's where developers can access information about the API and access keys</p>
+
+  	<p><a href="dashboard">Back to dashboard</a></p>
+
+	</div>
+</div>
+
+{% endblock %}