This macro allows embedding TOML data into the docs,
and showing it in a tab that has both the TOML and JSON
representation of that data.
It works by executing the toml2jsonc helper that was added
in an earlier commit.
There's some machinery here to compile that utility to run
in the context of the mkdocs docker image; that works
locally, let's see how well it works in CI!
Usage is simple; before:
```toml
["something"]
foo = "bar"
```
after:
{% call toml_data() %}
["something"]
foo = "bar"
{% endcall %}
The first page to get switched over to this is https://docs.kumomta.com/tutorial/configuring_kumomta/
refs: https://github.com/KumoCorp/kumomta/issues/212
Mike Hillyer
Ryan Bonnell
Wez Furlong
Mike Hillyer