1. Issue PR title prefixes (and labels)

Even when issue labels already indicate the areas and types of tickets (e.g. eng-docs or content-guide) it's useful to add a title prefix that reinforces the main purpose of an issue or pull request.

For example ref: update missing info about `exp init` may already have the content-ref label along with a few others, but the ref: prefix is the first thing one notices from the title, and quickly establishes what we're talking about.

Prefixes are especially helpful when a ticket covers several areas of the docs but has some other unifying factor e.g. exp init: update refs and guides for xyz reason.