Add ZeroSumTransform to docs

Author: AlexAndorra

docs/source/api/distributions/transforms.rst

@@ -33,6 +33,7 @@ Specific Transform Classes
     LogExpM1
     Ordered
     SumTo1
+    ZeroSumTransform
 
 
 Transform Composition Classes

pymc/distributions/multivariate.py

@@ -2422,7 +2422,7 @@ class ZeroSumNormal(Distribution):
         Necessary if ``shape`` is not passed.
     shape: tuple of integers, optional
         Shape of the distribution. Works the same as for other PyMC distributions.
-        Necessary if ``dims`` is not passed.
+        Necessary if ``dims`` or ``observed`` is not passed.
 
     Warnings
     --------

pymc/distributions/transforms.py

@@ -276,21 +276,20 @@ class ZeroSumTransform(RVTransform):
     Constrains any random samples to sum to zero along the user-provided ``zerosum_axes``.
     By default (``zerosum_axes=[-1]``), the sum-to-zero constraint is imposed
     on the last axis.
+
+    Parameters
+    ----------
+    zerosum_axes : list of ints
+        Must be a list of integers (positive or negative).
+        By default (``zerosum_axes=[-1]``), the sum-to-zero constraint is imposed
+        on the last axis.
     """
 
     name = "zerosum"
 
     __props__ = ("zerosum_axes",)
 
     def __init__(self, zerosum_axes):
-        """
-        Parameters
-        ----------
-        zerosum_axes : list of ints
-            Must be a list of integers (positive or negative).
-            By default (``zerosum_axes=[-1]``), the sum-to-zero constraint is imposed
-            on the last axis.
-        """
         self.zerosum_axes = tuple(int(axis) for axis in zerosum_axes)
 
     def forward(self, value, *rv_inputs):