Move docs out of the logging plugin directory

[colinmurphy]

Overview

We need to move the docs out of the WPGraphQL Logging Plugin and into the docs directory so they can be integrated with the docs site.

Criteria

1. Move docs under docs/plugins/wpgraphql-logging/
2. Add a index.md file for the docs/plugins
3. Update the https://github.com/wpengine/hwptoolkit/blob/main/docs/nav.json with the plugin docs (used to create sidebar navigation)

We also should use this opportunity

1. Verify the docs are correct
2. Add any missing filters from recent work
3. Update screenshots as these might incorrect due to changes
4. Update paths for finding settings etc as this has changed

[colinmurphy]

We are going to migrate other docs for other plugins too at the same time in effort to prepare for GA for the Headless Toolkit.