Update typography docs and Storybook theming

[VincentSmedinga]

This structures our typography documentation:

• Reorders and groups the sections
• Uses the Typeset doc block – with static font sizes or it will render long clamp labels
• Reformulates some of the guidelines
• Removes the maximum sentence length of 80 characters
• Mentions the font license and form

It also improves readability of our docs by enlarging the tiny prose text, applying our own font and increasing whitespace. There appears to be no better way to achieve this than to bluntly override CSS (see issues). Also textSize in themeConfig has no effect. Suggestions welcome, I do think we need the end result.

[dlnr]

Documentation looks great with the TypeSet component, great find!

[VincentSmedinga]

@alimpens I’ve applied your feedback to #803.