Move and update the description attribute to the correct place

[mmattel]

When using the attribute :description: which creates a meta tag in htm for search engines when rendered, you need to use two rules:

• It must be under the section header, not in aprticular order, but without a blank line above
• You must not use any links or attributes like xref:{url}[text] - will not get resolved and taken as it is

Found by chance. This PR corrects this for the docs-webui repo.

This will now make search engines print predefined text more likely than before when returning search results.