margins need to be fixed.

[jantuitman]

The text in a header is too close to the border. Bullets from the wiki component also come too close to the border.

[jantuitman]

bullets are fixed. remaining issues:

• lineheight are variable (lists have different line heights than regular text)
• headers have not enough vertical margins and are too close to the nearest top.
• h1/ h2/ h3 consistency and styling
• code boxes have not enough vertical margins.