How to add another announcement
First of all you need to setup another link to point to your announcement for the patch/plugin/lexer/template. To do so, click on "edit" besides the section you would like to add an announcment (e.g. the "edit" next to "Plugin announcements"). The easiest way is now to copy & paste a section that is already present. You might want to copy the link to the template for your announcement. After that chage the link's title to something meaningful, e.g. the name of your plugin. Make sure you choose this well because this will be the name oif the new WiKi section to be created. Once this is done save the changes. You'll now see a new link to a WiKi section (that has not content, yet). If you click on the new link a new (blank) page will open that will contain the description of the new WiKi anouncement. To add the announcement itself, open the related template WiKi article (e.g. "Template for plugin announcement"). Click on "edit" tab on the top of the page to edit the template (we are not going to change it). Copy the whole content and go back to the main annoucement WiKi section. Click on the link you've had created. The edit windo for this page will open since there is now content until now. Paste the content of the template and change it to fit your announcement. Finally click on the "Save page" button to create the new announcement in the WiKi.