Clarify expected behavior when providing a complex number array to nonzero (#441)

Author: kgryte

spec/API_specification/array_api/searching_functions.py

@@ -42,6 +42,12 @@ def nonzero(x: array, /) -> Tuple[array, ...]:
     """
     Returns the indices of the array elements which are non-zero.
 
+    .. note::
+       If ``x`` has a complex floating-point data type, non-zero elements are those elements having at least one component (real or imaginary) which is non-zero.
+
+    .. note::
+       If ``x`` has a boolean data type, non-zero elements are those elements which are equal to ``True``.
+
     .. admonition:: Data-dependent output shape
        :class: admonition important