Add missing aesara.tensor.random doc index

doc/library/tensor/random/index.rst

+.. _libdoc_tensor_random:
+
+=============================================
+:mod:`random` -- Low-level random numbers
+=============================================
+
+Low-level random numbers
+------------------------
+
+.. module:: aesara.tensor.random
+   :synopsis: symbolic random variables
+.. moduleauthor:: pymc-team
+
+The `aesara.tensor.random` module provides random-number drawing functionality
+that closely resembles the `numpy.random` module.
+
+.. toctree::
+    :maxdepth: 2
+
+    basic
+    utils
+
+
+.. automodule:: aesara.tensor.random.basic
+    :members: