Updates template for container-platform-telco

Author: aireilly

_templates/_page_openshift.html.erb

@@ -258,6 +258,7 @@
             </a>
             <select id="version-selector" onchange="versionSelector(this);">
               <option value="4.14">4.14</option>
+              <option value="4.15">4.15</option>
             </select>
         <% elsif (distro_key == "openshift-origin") %>
               <a href="https://docs.okd.io/<%= version %>/welcome/index.html">