Your coding agent can now check its template work against the real rules instead of guessing. @samva/markup ships a machine-readable contract and a reference that list which forms templates accept, which they refuse, and a fix for every error.
Point your agent at these two files:
@samva/markup/contract.json@samva/markup/generated/reference.md
The package also ships an sml skill under skills/sml.
New projects keep emails in templates/. Existing projects with an emails/ folder keep working, so nothing needs to move.