PIMD Classes Plugin

# Headline <?: .my-headline ?>

```html .my-code
<p>Example</p>
```

Lorem ipsum dolor sit amet. <?: .my-paragraph ?>

<h1 class="my-headline">Headline</h1>

<div class="pimd-example my-code">
  ...
</div>

<p class="my-paragraph">Lorem ipsum dolor sit amet.</p>

npm i pimd @pimd/classes-plugin

···
const { Document } = require("pimd")
const Config = require("pimd/lib/config")
const classesPlugin = require("@pimd/classes-plugin")

const config = new Config()
config.use(classesPlugin)

const markdown = `
···
# Headline <?: .my-headline ?>

\`\`\`html .my-code
<p>Example</p>
\`\`\`

Lorem ipsum dolor sit amet. <?: .my-paragraph ?>
`
const doc = new Document(markdown, config)
console.log(doc.render())