textproc/hevea: update to 2.36

Major changes:
    * OCaml 5.0 compatibility
    * Some petty optimisation in text output (replace ' '+ '\n' by '\n')
    * Correct bug in text mode

Full changelog: https://github.com/maranget/hevea/blob/master/CHANGES

Port changes:
    * Reorder variables to make linter happy