Rationalise links to CF in ANTS

# 📚 Documentation Request

## Addition
We need a consistent method to link to CF conventions throughout ANTS docs. In particular, we want to:

1. Always link to the latest version
2. Link to specific sections

In particular, the usage in the time appendix (appendix A) should be cleaned up - ideally, the definition of the link to CF should be migrated from this appendix over to `docs/source/conf.py`.

Start by inspecting the CF links in the time appendix (Appendix A) and the documentation configuration at docs/source/conf.py. Identify how the CF definition is currently handled, then make links consistently target the latest version and specific sections. Done means the appendix uses the shared definition and all relevant CF links are consistent.

Written by the indexing model from the issue text.