Add cookie banner text, page, and footer links

> Let’s start the footer links with the cookie page.
> Banner to say: "GOV.UK Notify uses cookies to make the site simpler. Find out
> more about cookies"
> Standard style one... see
> https://www.registertovote.service.gov.uk/register-to-vote/cookies or
> https://www.digitalmarketplace.service.gov.uk/cookies
>
> Let's link to the feedback form too...
> https://docs.google.com/forms/d/1AL8U-xJX_HAFEiQiJszGQw0PcEaEUnYATSntEghNDGo/viewform
> Call it Support and feedback

https://www.pivotaltracker.com/story/show/115483375

app/templates/views/cookies.html

@@ -0,0 +1,81 @@
+{% extends "withoutnav_template.html" %}
+
+{% block page_title %}
+  Cookies – GOV.UK Notify
+{% endblock %}
+
+{% block maincolumn_content %}
+
+<div class="grid-row">
+  <div class="column-two-thirds">
+    <h1 class="heading-xlarge">Cookies</h1>
+    <p class="summary">
+        GOV.UK Notify puts small files (known as ‘cookies’)
+        on to your computer.
+    </p>
+    <p>These cookies are used to remember you once you’ve logged in</p>
+    <p>
+        Find out <a href="http://www.aboutcookies.org/">how to manage cookies</a>.
+    </p>
+
+    <h2 class="heading-medium">Session cookies</h2>
+    <p>
+        We store session cookies on your computer to help keep your information
+        secure while you use the service.
+    </p>
+    <table>
+        <thead>
+            <tr>
+                <th>Name</th>
+                <th>Purpose</th>
+                <th>Expires</th>
+            </tr>
+        </thead>
+        <tbody>
+            <tr>
+                <td>
+                  notify_admin_session
+                </td>
+                <td width="50%">
+                  Used to keep you logged in
+                </td>
+                <td>
+                  1 hour
+                </td>
+            </tr>
+        </tbody>
+    </table>
+
+    <h2 class="heading-medium">Introductory message cookie</h2>
+    <p>
+        When you first use the service, you may see a pop-up ‘welcome’ message.
+        Once you’ve seen the message, we store a cookie on your computer so it
+        knows not to show it again.
+    </p>
+    <table>
+        <thead>
+            <tr>
+                <th>Name</th>
+                <th>Purpose</th>
+                <th>Expires</th>
+            </tr>
+        </thead>
+        <tbody>
+            <tr>
+                <td>
+                  seen_cookie_message
+                </td>
+                <td width="50%">
+                    Saves a message to let us know that you have seen our cookie
+                    message
+                </td>
+                <td>
+                  1 month
+                </td>
+            </tr>
+        </tbody>
+    </table>
+  </div>
+</div>
+
+{% endblock %}