Move and rename Application Security docs navigation item
Problem to solve
There is a disconnect between the naming "Secure" and its docs navigation naming "Application Security". The naming "Application Security" is appropriate, but it's not clear if this terms relates to security of the user's application or security controls within GitLab. The GitLab application security controls are listed in the documentation navigation under the title "Security".
- Move the existing "Secure" navigation item to elsewhere, likely the section aimed at the administrator.
Rename the "Application Security" navigation item
- Move the "Application Security" navigation item to be a top-level item.