create wizards for rest of statement types
sTeX environment types are documented at https://github.com/KWARC/sTeX/blob/master/sty/statements/statements.pdf. The assertion environment was implemented as a wizard in http://gl.kwarc.info/jucovschi/sider-stex-wizards/blob/master/src/main/resources/templates/assertion.html and can be accessed at http://localhost:8080/stex-wizards/app/assertion. The rest of statements need to be implemented as well.