docs: add SecObserve in CI/CD and reporting

[StefanFl]

Description

SecObserve is an open source vulnerability management system that can import and show results of Trivy and has it's own set of GitHub actions and GitLab templates. This shall be shown on the ecosystem pages for CI/CD and reporting.

Checklist

• I've read the guidelines for contributing to this repository.
• I've followed the conventions in the PR title.
• (N/A) I've added tests that prove my fix is effective or that my feature works.
• I've updated the documentation with the relevant information (if needed).
• (N/A) I've added usage information (if the PR introduces new options)
• (N/A) I've included a "before" and "after" example to the description (if the PR is a user interface change).

[CLAassistant]

All committers have signed the CLA.