Weave in the SEO guidance

**Is your feature request related to a problem? Please describe.**
We have some notes from Michael (https://trello.com/c/BYqIcOn6/2480-ees-seo-guidance)
We also have some notes and a slide pack of guidance from the Get Into Teaching team

**Describe the solution you'd like**
We should include these notes in the appropriate places in the EES guidance on the analysts guide

**Describe alternatives you've considered**
Could have a separate SEO page, but I think this is better in the places it relates to, it should be normalised to think of SEO when deciding on a title or a summary, or what content you produce.

**Additional context**
Cam has the links for these materials

Start by obtaining the SEO notes from the Trello card, the Get Into Teaching slide pack, and Cam, then review the existing EES guidance in the analysts guide to identify the pages covering titles, summaries, and content creation. Place the relevant guidance in those existing sections rather than creating a separate SEO page, and confirm the resulting pages consistently address SEO.

Written by the indexing model from the issue text.