chore: Prepare plugin, example, explanation, and how-to docs for release

[ahuseyn]

As a part of releasing the documentation to general availability (#455 ), we need to prepare explanation and how-to docs to make sure it renders well on the website. We need to make sure the code snippets rendering correctly and the links are intact.

Documentation below should be prepared for the website:

• WPGraphQL Logging Plugin
• HWP Previews
• How-to docs
• Explanation docs
• Examples