This wiki requires users to register before they can edit content on the site. The purpose of this is to track user contributions. If you would like to edit content, but do not be wished to be tracked yourself, then you should select a user name for this site that cannot be tracked back to you.
The email address that you supply for access recovery if you forget or lose your credentials (aka password) will not be shared by others beyond the administrators of the site. Still, if that is not sufficient confidentiality for your, feel free to establish a pseudonym for your email and user name with some free email service.