Update help center articles

[fditrapani]

Problem

In some cases, the title formatting and open guide link in the help center guides breaks:

But it's not always the case:

I'm unsure if it's a wp-admin vs. calypso thing or simple site vs. atomic. The latter option is the right way to go. I would maybe add a little bit more space for the guide link so that it's more noticeable. I changed the title's top margin from 8px to 16px:

Where

• Open the help center
• Search with guides for long names

[github-actions]

OpenAI suggested the following labels for this issue:

• [Feature Group] Help Center: The issue directly relates to improvements and updates needed in the help center articles and guides.
• [Feature] Support Docs Content: This label applies because the issue discusses updating the content of support documentation in the help center.
• [Feature] Design: The mention of formatting changes, such as modifying margins to improve visibility, indicates an aspect of design enhancement.