Update markdownify to 0.12.1

[pyup-bot]

This PR updates markdownify from 0.11.6 to 0.12.1.

Changelog

0.12.0

Huge thanks to all the contributors!

What's Changed
* improve text normalization/escaping for preformatted/code contexts by chrispy-snps in https://github.com/matthewwithanm/python-markdownify/pull/104
* ignore script and style content (such as css and javascript) by tlk in https://github.com/matthewwithanm/python-markdownify/pull/112
* Add no css example to readme by GeeCastro in https://github.com/matthewwithanm/python-markdownify/pull/111
* Fix newline start in header tags by 5yato4ok in https://github.com/matthewwithanm/python-markdownify/pull/89
* Fix newlines in tables by carantunes in https://github.com/matthewwithanm/python-markdownify/pull/91
* Strip text before adding blockquote markers by andredelft in https://github.com/matthewwithanm/python-markdownify/pull/76
* revert workaround example in README.md for `<script>` and `<style>` by chrispy-snps in https://github.com/matthewwithanm/python-markdownify/pull/115
* Support conversion of header rows in tables without th tag by huuyafwww in https://github.com/matthewwithanm/python-markdownify/pull/83
* make sure there are blank lines around table/figure captions by chrispy-snps in https://github.com/matthewwithanm/python-markdownify/pull/114
* Table merge cell horizontally by xydxydxyd1 in https://github.com/matthewwithanm/python-markdownify/pull/110

New Contributors
* chrispy-snps made their first contribution in https://github.com/matthewwithanm/python-markdownify/pull/104
* tlk made their first contribution in https://github.com/matthewwithanm/python-markdownify/pull/112
* GeeCastro made their first contribution in https://github.com/matthewwithanm/python-markdownify/pull/111
* 5yato4ok made their first contribution in https://github.com/matthewwithanm/python-markdownify/pull/89
* carantunes made their first contribution in https://github.com/matthewwithanm/python-markdownify/pull/91
* huuyafwww made their first contribution in https://github.com/matthewwithanm/python-markdownify/pull/83
* xydxydxyd1 made their first contribution in https://github.com/matthewwithanm/python-markdownify/pull/110

**Full Changelog**: https://github.com/matthewwithanm/python-markdownify/compare/0.11.6...0.12.0

Links

• PyPI: https://pypi.org/project/markdownify
• Changelog: https://data.safetycli.com/changelogs/markdownify/
• Repo: http://github.com/matthewwithanm/python-markdownify/tarball/master