Release notes V0.13

• Reset all user pronouns. After gathering some feedback, we decided to get rid of the predefined dropdown list, so that you can now define your own preferred pronouns!
• Updated the forum URL's to be more SEO friendly. For example: https://artgalaxy.co/forum/marketplace/digital-art.
• Made some more preparations regarding user galleries. Nothing is available yet, so far the only visible changes are that each tab on the user profile has now it's own dedicated link. For example: https://artgalaxy.co/user/vex/gallery. In the future, this will be important so that all user galleries will have their own links as in "/user/vex/gallery/{gallery-name}".