Constructs a rate limit from a max order count and a window.
windowMs is the rolling-window length in milliseconds. Fractional
milliseconds retain nanosecond precision.
Throws TypeError when maxOrders is not a number, or RangeError
when maxOrders is not an exact non-negative integer in the supported
range or windowMs cannot be represented as a native duration. Positive
and maximum-window validation is performed by the core settings
constructor when the policy is built.
Rate-limit configuration: a maximum order count over a rolling window.