Prepare for test modules sharing PrettyShow.

Prepare for test modules sharing font options.

Make demo font size better match window.

Separate internal plain Paragraph/ParagraphLayout.

Implement BiDi resolved level reordering.

Fix style: long lines.

Fix style: small Prelude imports.

Fix style: external vs internal imports.

Fix style: unnecessary do notation.

Fix style: white space in lambdas.

Fix style: white space around operators.

Fix style: white space in multi-line lists.

Fix style: white space in exports and imports.

Fix style: bullet points in comments.

Fix style: remove duplicate spaces.

Mark some lists as explicitly non-empty.

Fix typos in comments.

Fix data types in harfbuzz-pure.

Add paragraph pagination.

Implement generic pagination internally.