Update security docs
What's Changed
- Updated introductory paragraph in Secure your application index page
- Added pages for Scan Results and Remediation and Other Security Scans
- Removed the outdated Generated Reports page
Why
- Updates required for reflecting new security features that come with GitLab Ultimate
Sections Affected
- Secure your application
How was it tested
- Checked MD preview on online GitLab IDE
Anything Else
-