ANN: pandoc 2.17

[John MacFarlane]

I'm pleased to announce the release of pandoc 2.17,
available in the usual places:

Binary packages & changelog:
https://github.com/jgm/pandoc/releases/tag/2.17

Source & API documentation:
http://hackage.haskell.org/package/pandoc-2.17

In addition to the usual under-the-hood improvements
and bug fixes, there are some new features:

* `markua` (a Markdown variant used by Leanpub) is now supported as an
output format.
* `--wrap=auto` will now wrap HTML output.
* Custom (Lua) readers can now access the full list of sources,
not just the concatenated text.
* Official Org-cite citations are now supported in Org mode.
* Counter cookies and (with the fancy_lists extension)
alphabetical lists are supported in Org mode.
* Custom (Lua) writers can now set template variables and access
pandoc writer options.
* `r-stretch` classes can be attached to images in reveal.js, and
`r-fit-text` classes can be attached to headers.
* HTML and EPUB templates now support abstracts.
* Powerpoint now uses a 16:9 aspect ratio by default.
* The Lua subsystem has many improvements, giving filters
writers much more power (top down traversals, control
over pandoc writers, access to bibliographic, and more:
see changelog for details.)

API changes:

* Export writeMarkua from Text.Pandoc.Writers.Markdown.
* Do not export writeCustom from Text.Pandoc.Writers.
* Text.Pandoc.Filter.applyFilters now takes a filter environment
of type Environment, instead of a ReaderOptions value.
* Text.Pandoc.Filter exports the Environment type.
* Global in Text.Pandoc.Lua has a new constructor PANDOC_WRITER_OPTIONS.

See the changelog for full details.

Thanks to all who contributed, including Albert Krewinkel,Jörn
Krenzer, Kolen Cheung, Martin Fischer, Mauro Bieg, Michael
Hoffmann, and new contributors Jannik Buhr, Jesse Hathaway,
Lucas Viana, Tuong Nguyen Manh, Tim Wisotzki and Saumel
Lemmenmeier.