Update docstring for model.point_logps (#5505)

* Updated docstring for model.point_logps

* Updated docstring for model.point_logps

Author: purna135

pymc/model.py

@@ -1693,11 +1693,11 @@ def point_logps(self, point=None, round_vals=2):
 
         Parameters
         ----------
-        point: Point
+        point: Point, optional
             Point to be evaluated.  If ``None``, then ``model.initial_point``
             is used.
-        round_vals: int
-            Number of decimals to round log-probabilities
+        round_vals: int, default 2
+            Number of decimals to round log-probabilities.
 
         Returns
         -------