The manual's "Defining Functions" section shows only one-argument
functions, so it never says how to pass more than one. This adds a short
paragraph: arguments are separated by `;` in both `def f(a; b):` and
`f(.x; .y)`, and `f(.x, .y)` instead calls a one-argument `f` with the
filter `.x, .y`. It also adds an example for each. `tests/man.test` and
`jq.1.prebuilt` are regenerated.
Fixes#2163
qodelicious
49fbca1242