...generously Gideon (the author of Q&A) allows to remove this "powered by..." hint - but you should think over if you really want to withhold this tribute to him ;)
If you type "powered by" into the search-field this is one of the first hits:
http://www.question2answer.org/qa/6602/how-do-you-remove-the-powered-by
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.