style: improve rendering of Notion content

[uniqueg]

Description of problem

Content pulled from Notion to render tile views looks well enough. However, the rendering for more complex free form content (i.e., involving lists, callouts, quotes) is difficult to read and rather ugly/untidy. As an example, see the rendered /about page:

It looks much cleaner in Notion itself:

Possible solution

It would be nice to change the styling, for example in the following ways:

• Indent bullet points in lists
• Increase padding, left-align text and change background color in callouts
• Change font for quotes (see style: change quote style/font #61)
• Limit viewport width for all pages; for example, use same width as is used for Twitter feed in /news)