[fixmystreet.com] Rename goodies images/PDFs.

Fixes #987.

templates/web/fixmystreet.com/static/posters.html

@@ -132,16 +132,16 @@ <h2 id="adverts">Pre-made Adverts</h2>
 <p>Ideal for promoting FixMyStreet in your community newsletter or local magazine. Specially designed to stand out, and get your message across!</p>
 
 <ul class="downloads">
-    <li><a href="/cobrands/fixmystreet/posters/fixmystreet-advert-90x130.pdf" data-goodielink="fixmystreet-advert-90x130">
-        <img src="/cobrands/fixmystreet/images/advert-90x130.png">
+    <li><a href="/cobrands/fixmystreet/posters/fixmystreet-promote-90x130.pdf" data-goodielink="fixmystreet-advert-90x130">
+        <img src="/cobrands/fixmystreet/images/promote-90x130.png">
         <strong>Quarter page advert</strong> (9cm wide, 13cm high)
     </a></li>
-    <li><a href="/cobrands/fixmystreet/posters/fixmystreet-advert-90x60.pdf" data-goodielink="fixmystreet-advert-90x60">
-        <img src="/cobrands/fixmystreet/images/advert-90x60.png">
+    <li><a href="/cobrands/fixmystreet/posters/fixmystreet-promote-90x60.pdf" data-goodielink="fixmystreet-advert-90x60">
+        <img src="/cobrands/fixmystreet/images/promote-90x60.png">
         <strong>One-eighth page advert</strong> (9cm wide, 6cm high)
     </a></li>
-    <li><a href="/cobrands/fixmystreet/posters/fixmystreet-advert-40x60.pdf" data-goodielink="fixmystreet-advert-40x60">
-        <img src="/cobrands/fixmystreet/images/advert-40x60.png">
+    <li><a href="/cobrands/fixmystreet/posters/fixmystreet-promote-40x60.pdf" data-goodielink="fixmystreet-advert-40x60">
+        <img src="/cobrands/fixmystreet/images/promote-40x60.png">
         <strong>One-sixteenth page advert</strong> (4cm wide, 6cm high)
     </a></li>
 </ul>