How to add a new explorable component / basic setup of articles and interactives for explorables

[P3nny]

• explorable articles are stored as mdx pages in the datenguide/datenguide repo (comparable to blog articles)
• components are developed inside the storybook

To write a new component:
In /storybook:
- add a new component.js file in explorables/components
- add a component.stories.js file in explorables/stories
- publish the component as npm package

To use the new component in a explorable article:
In datenguide/datenguide:
- clone the explorable template
- import the components you need via npm
- import and use the components in your mdx article file