[Docutils-users] Incomplete unit listing

[Anton H. <to...@ar...>]

Hi.

It appears there's some units missing from: 
https://github.com/docutils/docutils/blob/b768e2626088711dec257b0847b563d02700a712/docutils/docutils/parsers/rst/directives/__init__.py#L240

Namely: vh, vw, vmin, vmax, lvh, dvh, svw, lvw, dvw, svmin, lvmin, 
dvmin, svmax, lvmax, dvmax, vi, svi, lvi, dvi, vb, svb, lvb and dvb

These are part of the new HTML/CSS viewport units and are are/will be 
part of CSS templates: 
https://web.archive.org/web/20240114171725/https://www.terluinwebdesign.nl/en/css/incoming-20-new-css-viewport-units-svh-lvh-dvh-svw-lvw-dvw/

If these are not compatible for some reason, perhaps they could be given 
as a complementary argument to 
https://github.com/docutils/docutils/blob/b768e2626088711dec257b0847b563d02700a712/docutils/docutils/parsers/rst/directives/__init__.py#L262C5-L262C23 
for instance?

I'm coming from a sphinx usage, where rendering HTML with CSS is the 
base concept.
Where I might have a reST similar to:

```
Some Header
===========


.. list-table::

    * - .. figure:: /_static/a_picture.webp
           :width: 25dvw

```

And when running `make build` I'll hit: 
https://github.com/docutils/docutils/blob/b768e2626088711dec257b0847b563d02700a712/docutils/docutils/parsers/rst/directives/__init__.py#L256-L258

Because `units` is equal to `length_units` which is missing the unit dvw.

//Anton