Standardize the blockquote "Notes" usage, so all places are using the
`>` blockquote notation, as well as a consistent style for the "Note"
word.
PS: Thought that bolding the word "**Note**" would make for a higher
visual distinction, so went for it in all existing cases! No strong
feelings, though; happy to roll back to just "Note:" if that's
preferrable!
Release Notes:
- N/A
