Clarify `==` docs for collections (#52495)
Alright, here's my spitball at fixing
https://github.com/JuliaLang/julia/issues/52484.
This also clarifies the non-missing behaviors, and adds a reference to
`all` which should be a useful breadcrumb. I don't want to say `all(x
.== y)` because that has all sorts of broadcasting semantics, but we
could perhaps add a comparison to `all(splat(==), zip(x, y))` or
`all(map(==, x, y))`, but even those feel sketchy to reference as they
may miss other properties (like array shape).
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Co-authored-by: Jameson Nash <vtjnash@gmail.com>
Co-authored-by: inky <git@wo-class.cn>
Co-authored-by: Max Horn <max@quendi.de>
