Description

In the guide's section on page setup, it says that paper sizes such as "iso-a4" are supported: https://typst.app/docs/guides/page-setup-guide/

Options include the complete ISO 216 series (e.g. "iso-a4", "iso-c2"),
customary US formats like "us-legal" or "us-letter", and more.

However, the actual behavior doesn't allow the "iso-" prefix for the A* series.

% cat tutorial.typ 
#set page(paper: "iso-a4")
% typst --version
typst 0.13.0 (8dce676d)
% typst compile tutorial.typ
error: expected "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", "a8", "a9", "a10", "a11", "iso-b1", "iso-b2", "iso-b3", "iso-b4", "iso-b5",
[...]

IMO the values "a4" and "iso-a4" should both be accepted, as synonyms (ditto other A* sizes). But if it's intended that "iso-a4" isn't a valid value for that parameter, then the docs should be adjusted to match.