docs(report): fix reporting doc format

[pbaumard]

Description

The list format is broken in https://aquasecurity.github.io/trivy/dev/docs/configuration/reporting/#sarif since an empty line is required before the list.

The markdown parser used for Trivy documentation is stricter than the one used by GitHub.

The list punctuation is also now more consistent in the document.

Related PRs

• docs(report): Improve SARIF reporting doc #7655

Checklist

• I've read the guidelines for contributing to this repository.
• I've followed the conventions in the PR title.
• 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).
• I've added usage information (if the PR introduces new options)
• I've included a "before" and "after" example to the description (if the PR is a user interface change).