Update doc for the new export feature

templates/default/documentation.html.ep

@@ -113,9 +113,22 @@
           </li>
           <li>The following perl modules are optional
             <ul>
+              <li>
+                For Etherpad-Lite support:
+                <ul>
                   <li>Etherpad::API</li>
                 </ul>
               </li>
+              <li>
+                To export events in a XLSX file
+                <ul>
+                  <li>Mojolicious::Plugin::RenderFile</li>
+                  <li>File::Temp</li>
+                  <li>Excel::Writer::XLSX</li>
+                </ul>
+              </li>
+            </ul>
+          </li>
         </ul>
         It's also advised to run VROOM on a systemd powered distribution (simply because that's what I use and I include service units for VROOM). 
         For the same reason, I recommend running Apache as webserver (others like Nginx probably work too, but I provide configuration sample only for Apache)
@@ -179,7 +192,8 @@ yum install git tar wget httpd mod_ssl openssl mariadb-server \\
            'perl(Mojolicious)' 'perl(Mojolicious::Plugin::I18N)' 'perl(Mojolicious::Plugin::Mail)' \\
            'perl(Crypt::SaltedHash)' 'perl(Etherpad::API)' 'perl(LWP::Protocol::https)' \\
            'perl(Sesion::Token)' 'perl(Mojolicious::Plugin::Database)' \\
-           'perl(Mojolicious::Plugin::StaticCompressor' 'perl(Email::Valid)' \\
+           'perl(Mojolicious::Plugin::StaticCompressor' 'perl(Mojolicious::Plugin::RenderFile)' \\
+           'perl(Email::Valid)' 'perl(File::Temp)' 'perl(Excel::Writer::XLSX)' \\
            'perl(Config::Simple)' 'perl(Session::Token)' 'perl(DateTime)'</pre>
       </p>