This PR includes many small-ish changes:
- Fixing typos
- Grammar/punctuation improvements
- Fixing formatting of lists
- Converting HTML tables to Markdown
- Making plain URLs into clickable links
- Re-ordering paragraphs in the page about Ion
It also significantly changes page ch13-03.
Each commit's message explains/justifies that commit's changes.
The book builds fine after these changes, but the CI pipeline is broken so it fails anyways.