Default parameter option `evals_set` is not documented

Hi there,

maybe I miss something completely, but I do not understand the meaning of samples and evals for the benchmarks.

If I run this code in REPL

using BenchmarkTools
BenchmarkTools.DEFAULT_PARAMETERS.samples = 1
BenchmarkTools.DEFAULT_PARAMETERS.evals = 1

foo_calls = 0

function foo()
  global foo_calls += 1
end

b = @benchmark foo()

@show foo_calls

b

it should, as I understood the documentation, evaluate foo once. However, it produces

foo_calls = 501494
BenchmarkTools.Trial: 1 sample with 993 evaluations.
 Single result which took 37.263 ns (0.00% GC) to evaluate,
 with a memory estimate of 16 bytes, over 1 allocations.

Why does it evaluate foo 993 times while it was called in reality 501494 times?

Start with BenchmarkTools.DEFAULT_PARAMETERS and the @benchmark entry point shown in the reproduction. Read the existing benchmark documentation around samples and evals, then document evals_set and clarify why the displayed evaluation count differs from foo_calls. Done means the parameter behavior and the observed output are explained in the documentation.