Sort definition vector by section/name
Sort definition vector by section/name

This is the expected order by Kate, thus simplifying the migration.

janusw/syntax-highlighting,janusw/syntax-highlighting,janusw/syntax-highlighting,janusw/syntax-highlighting,janusw/syntax-highlighting,janusw/syntax-highlighting,janusw/syntax-highlighting,janusw/syntax-highlighting,janusw/syntax-highlighting,janusw/syntax-highlighting,janusw/syntax-highlighting,janusw/syntax-highlighting