Sure, Steem.center is a wiki, like Wikipedia, where everyone can create and edit any page. You can use the Sandbox to play and try wiki editions. To create a new page or update an existent one just click in the edit link in top menu. New pages are created from links generated (appear in red) when you write the suggested new page title between double brackets. If need help you can reply here, use the MediaWiki tutorial or ask for a personal response in Steemit.chat #wiki channel. Thanks and good luck again!