Update bounds docstring in dataarray also

Author: mgunyho

xarray/core/dataarray.py

@@ -6152,10 +6152,12 @@ def curvefit(
             broadcast to the coordinates of the array. If none or only some parameters are
             passed, the rest will be assigned initial values following the default scipy
             behavior.
-        bounds : dict-like or None, optional
-            Optional dictionary of parameter names to bounding values passed to the
-            `curve_fit` `bounds` arg. If none or only some parameters are passed, the rest
-            will be unbounded following the default scipy behavior.
+        bounds : dict-like, optional
+            Optional dictionary of parameter names to tuples of bounding values passed to the
+            `curve_fit` `bounds` arg. If any of the bounds are DataArrays, they will be
+            appropriately broadcast to the coordinates of the array. If none or only some
+            parameters are passed, the rest will be unbounded following the default scipy
+            behavior.
         param_names : sequence of Hashable or None, optional
             Sequence of names for the fittable parameters of `func`. If not supplied,
             this will be automatically determined by arguments of `func`. `param_names`