Add section to Pipeline SD docs on detecting complex strings
What does this MR do and why?
This merge request adds a new section to the Pipeline Secret Detection documentation on detecting complex strings like passwords. It uses a sample rule adjusted from gitleaks default ruleset's generic-api-key
rule to be a little more sensible for passwords, and explains the regex pattern and how it could be used to extend GitLab's default ruleset with password detection.
Resolves #468087 (closed).
MR acceptance checklist
I have evaluated this MR against the MR acceptance checklist.
Edited by Ahmed Hemdan