docs: add hint definition for native inputs

std/math/emulated/field_hint.go

@@ -189,6 +189,18 @@ func (f *Field[T]) NewHintWithNativeOutput(hf solver.Hint, nbOutputs int, inputs
 // non-native elements. There is [UnwrapHintWithNativeInput] function which
 // performs corresponding recomposition of limbs into integer values (and vice
 // verse for output).
+//
+// This method is an alternation of [NewHint] method, which allows to pass
+// native inputs to the hint function and returns nonnative outputs. This is
+// useful when the inputs do not necessarily have to be emulated elements (e.g.
+// indices) and allows to work between different fields.
+//
+// The hint function for this method is defined as:
+//
+//	func HintFn(nativeMod *big.Int, nativeInputs, nativeOutputs []*big.Int) error {
+//	    return emulated.UnwrapHintWithNativeInput(nativeInputs, nativeOutputs, func(emulatedMod *big.Int, inputs, outputs []*big.Int) error {
+//	        // in the function we have access to both native and nonantive modulus
+//	    })}
 func (f *Field[T]) NewHintWithNativeInput(hf solver.Hint, nbOutputs int, inputs ...frontend.Variable) ([]*Element[T], error) {
 	nativeInputs := f.wrapHintNatives(inputs...)
 	nbNativeOutputs := int(f.fParams.NbLimbs()) * nbOutputs