Markdown-it-py

This release provides some improvements to the code base:

- 🐛 FIX: Do not resolve backslash escapes inside auto-links
- 🐛 FIX: Add content to image tokens
- 👌 IMPROVE: Add more type annotations, thanks to [hukkinj1](https://github.com/hukkinj1)

🗑 DEPRECATE: Move plugins to `mdit_py_plugins`

Plugins (in `markdown_it.extensions`) have now been moved to [executablebooks/mdit-py-plugins](https://github.com/executablebooks/mdit-py-plugins).
This will allow for their maintenance to occur on a different cycle to the core code, facilitating the release of a v1.0.0 for this package

🔧 MAINTAIN: Add [mypy](https://mypy.readthedocs.io) type-checking, thanks to [hukkinj1](https://github.com/hukkinj1).

✨ NEW: Add linkify, thanks to [tsutsu3](https://github.com/tsutsu3).

This extension uses [linkify-it-py](https://github.com/tsutsu3/linkify-it-py) to identify URL links within text:

- `github.com` -> `<a href="http://github.com">github.com</a>`

**Important:** To use this extension you must install linkify-it-py; `pip install markdown-it-py[linkify]`

It can then be activated by:

python
from markdown_it import MarkdownIt
md = MarkdownIt().enable("linkify")
md.options["linkify"] = True

✨ NEW: Add smartquotes, thanks to [tsutsu3](https://github.com/tsutsu3).

This extension will convert basic quote marks to their opening and closing variants:

- 'single quotes' -> ‘single quotes’
- "double quotes" -> “double quotes”

It can be activated by:

python
from markdown_it import MarkdownIt
md = MarkdownIt().enable("smartquotes")
md.options["typographer"] = True


✨ NEW: Add markdown-it-task-lists plugin, thanks to [wna-se](https://github.com/wna-se).

This is a port of the JS [markdown-it-task-lists](https://github.com/revin/markdown-it-task-lists),
for building task/todo lists out of markdown lists with items starting with `[ ]` or `[x]`.
For example:

markdown
- [ ] An item that needs doing
- [x] An item that is complete


This plugin can be activated by:

python
from markdown_it import MarkdownIt
from markdown_it.extensions.tasklists import tasklists_plugin
md = MarkdownIt().use(tasklists_plugin)


🐛 Various bug fixes, thanks to [hukkinj1](https://github.com/hukkinj1):

- Do not copy empty `env` arg in `MarkdownIt.render`
- `_Entities.__contains__` fix return data
- Parsing of unicode ordinals
- Handling of final character in `skipSpacesBack` and `skipCharsBack` methods
- Avoid exception when document ends in heading/blockquote marker

🧪 TESTS: Add CI for Python 3.9 and PyPy3

- ✨ NEW: Add simple typographic replacements, thanks to [tsutsu3](https://github.com/tsutsu3):
This allows you to add the `typographer` option to the parser, to replace particular text constructs:

- ``(c)``, ``(C)`` → ©
- ``(tm)``, ``(TM)`` → ™
- ``(r)``, ``(R)`` → ®
- ``(p)``, ``(P)`` → §
- ``+-`` → ±
- ``...`` → …
- ``?....`` → ?..
- ``!....`` → !..
- ``????????`` → ???
- ``!!!!!`` → !!!
- ``,,,`` → ,
- ``--`` → &ndash
- ``---`` → &mdash

python
md = MarkdownIt().enable("replacements")
md.options["typographer"] = True


- 📚 DOCS: Improve documentation for CLI, thanks to [westurner](https://github.com/westurner)
- 👌 IMPROVE: Use `re.sub()` instead of `re.subn()[0]`, thanks to [hukkinj1](https://github.com/hukkinj1)
- 🐛 FIX: An exception raised by having multiple blank lines at the end of some files

👌 IMPROVE: Add `store_labels` option.

This allows for storage of original reference label in link/image token's metadata,
which can be useful for renderers.