docs: Add missing TOC entries

[kevgo]

Proposed changes

The TOC in this file is outdated. Are you still using doctoc as the comments in various MD files indicate? It's not included in package.json. Setting it up seems not straightforward since it adds TOCs everywhere so I wanted to check in about this first before hacking on this.

Checklist

• I have read the contributing guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security. vulnerability, I
  confirm that I got green light (please contact
  security@ory.sh) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.