docs: Added info on repo-config.yaml and tables of contents

[itoltz]

secureli-397

Issue was for adding documentation about config files. There wasn't much more that needed to be added in that regard. I also added tables of contents to README.md and CONTRIBUTING.md. The tables of contents were generated with the VSCode plugin Markdown All in One.

Changes

• Added section describing the nature of repo-config.yaml
• Added tables of contents to README.md and CONTRIBUTING.md

Testing

• n/a

Clean Code Checklist

• Meets acceptance criteria for issue
• New logic is covered with automated tests
• Appropriate exception handling added
• Thoughtful logging included
• Documentation is updated
• Follow-up work is documented in TODOs
• TODOs have a ticket associated with them
• No commented-out code included

[github-actions]

PR title failed to match (chore|style|test|feat|fix|docs|ci): .+

All good!