This change conceals `full_reference_link`, `collapsed_reference_link`,
and `shortcut_link` similarly to the `markdown_inline` query file
already conceals `inline_link` and `image`.
## Test markdown contents
```markdown
Some text before the link [full reference link text][link label] and now some
text after the link onto a new line.
Some text before the link [collapsed reference link text][] and now some text
after the link onto a new line.
Some text before the link [shortcut link text] and now some text after the link
onto a new line.
```
## Test markdown concealed screenshot
Closes#3267
* switch to split markdown parser with separate block and inline parsers to improve performance
* add exclude_children! directive (useful for something like Injected markdown incorrectly highlights indented docstrings #2212)
* split markdown queries into block and inline ones and add the injection for inline into block grammar
* add include_dir option to parser configs (needed because the two grammars don't live in the repos root directory)
BREAKING CHANGE: downstream queries need to be adapted to new parser
