Welcome to the eHealth Africa wiki. As you can see from the navigation above, the wiki is divided into "spaces". There's a space for each Project, a space for each Department, and a space for each Office. The designated person who is responsible for each space is then free to add whatever information they like (within reason), but the assumption is that everything should be stored in or linked to from the relevant space.
You can create new pages in a space, then drag in files, paste images, embed task lists, user mentions, JIRA tickets, and Google Drive docs and folders. The value of a wiki is directly related to the quantity of content on it, so don't hold back!