style: add padding between text and images on getting started and include necessary subheaders

[tobySolutions]

Why?

Text blocks and paragraphs on the "Getting started" page were getting choked up between images and were generally too close to images. This fix makes things look way more appealing. This PR adds subheaders that were not formerly visible in the right-hand-side content navigation.

Contribution checklist?

• The commit messages are detailed
• The build command runs locally
• Assets or static content are linked and stored in the project
• Document filename is named after the slug
• You've reviewed spelling using a grammar checker
• For documentation, guides or references, you've tested the commands and steps
• You've done enough research before writing

[changeset-bot]

⚠️ No Changeset found

Latest commit: d7c8d47

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[nlc616]

LGTM