DEV-16531: Implement `addWebcShortcode` in `shortcodeFactory`

[anderspollack]

• Update @11ty/eleventy-plugin-webc to version 0.11.1
• Implement addWebcShortcode in shortcodeFactory

I'm definitely open to different ways of serializing attributes for webc components. Since we don't have keyword args in liquid, I was thinking we would have to specify the argument names when registering shortcodes:

component registration:

addWebcShortcode('gradoo, 'gradoo-component', ['foo', 'bar'])

liquid template

{% gradoo 'hello' 'goodbye' %}

webc template

<gradoo-component foo="hello" bar="goodbye"></gradoo-component>