Fix doc string typos
Fix doc string typos

qwe2/websharper.ui.next,Micha-kun/websharper.ui.next,intellifactory/websharper.ui.next,intellifactory/websharper.ui.next,intellifactory/websharper.ui.next,Micha-kun/websharper.ui.next,ChrisDobby/websharper.ui.next