swap arguments to fix \marginpar[<left>]{<right>} behavior

Swapping arguments to fix `\marginpar[<left>]{<right>}` behavior. Fixes #1

`\marginpar[<left>]{<right>}` does not work correctly under marginfix v0.9.1.
The `<left>` and `<right>` notes are swapped.
Swapping arguments to fix `\marginpar[<left>]{<right>}` behavior.