`mdoc` table-of-contents generator

This plugin enables generating a table of contents for markdown files using mdoc by adding the following code:

```scala mdoc:toc
```

Installation

Add the following line to your plugins.sbt file:

addSbtPlugin("com.alejandrohdezma" % "sbt-mdoc-toc" % "0.4.2")

Just add the following where you want to add the table of contents in your markdown file:

```scala mdoc:toc
```

And run sbt mdoc.