Improve documentation consistency for security tool configuration

UX Scorecard recommendation from: gitlab-design#1829

Problem to solve

The documentation outlining the steps to enable a security scanner via the UI is not consistent across tools. Standardizing this content will make it easier for users to recognize and leverage the configuration steps from one scanner when enabling another.

Scanner	UI configuration docs
Secret Detection
Dependency Scanning
IaC
SAST
DAST
API Fuzzing

Recommendation

Audit the documentation for each security scanner and standardize how common steps are explained.