Move Creating a PAT section before Notifications for Expired

What does this MR do?

Moves a section that is more important to new users towards the top of the documentation page for Personal Access Tokens based on a wider community suggestion #239471 (closed)

As a fairly new GitLab user, and someone who had never heard of a Personal Access Token, I realized the answer to my problem was on the page, it was just further down the page ....Add the 'Creating a Personal Access Token' section to the top of the page, just after the short description of what the token is.

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Closes #239471 (closed)