add sloppypar env to latex-document.cwl

[muzimuzhi]

Fixes #4675.

See doc https://latexref.xyz/sloppypar.html.

[sunderme]

Thanks

[mbertucci47]

This and other commands from l2tabu are in latex-l2tabu.cwl (predating my time). Do we want to add all these, perhaps with #S, to latex-document.cwl? They are valid commands but as documented in the linked pdf are not recommended.

[muzimuzhi]

@mbertucci47 I proposed some follow-ups in #4680.

The remaining work is to read through the latest l2tabu.pdf v2.4 (2016-02-03) then update latex-l2tabu.cwl accordingly, if needed.

[sunderme]

This and other commands from l2tabu are in latex-l2tabu.cwl (predating my time). Do we want to add all these, perhaps with #S, to latex-document.cwl? They are valid commands but as documented in the linked pdf are not recommended.

I am fine with merging the two cwl.
It is not txs' job to teach users what to use.

[muzimuzhi]

@sunderme Then I think it's safe to remove latex-l2tabu.cwl and references to it.

I'll prepare a PR.