publish.example_missing: Package's function has no example, or a failure it raises is shown by none

Package's function has no example, or a failure it raises is shown by none.

Area 14, Tooling; not declinable; the next step is usually the agent's.

Every function of a public library has an example in its description, and each failure it can raise is shown by an example or a test:

text

$ jadpo package checkerror: Function `uk.tidy` has no example --> libraries/uk.jadpo:6:14  |6 |     function tidy(entered: EnteredPostcode) fails InvalidPostcode -> UkPostcode {  |              ^^^^ no example in its description  reason: Every function of a published library shows how it is called with an example in its description, a ```jadpo block run as a test, so what the registry's page and `jadpo package show` say of it always runs.  next: Add a ```jadpo block to `uk.tidy`'s `///` description, holding statements as a test does: `assert uk.tidy(...) == ...` (agent)  rule: publish.example_missing  help: https://jadpo.dev/docs/errors/publish.example_missing

A failure no example or test asserts with fails is reported the same way, as "uk.tidy can fail with InvalidPostcode, which no example or test shows".