Update API reference listings

Author: ricardoV94

docs/api_reference.rst

@@ -9,13 +9,40 @@ methods in the current release of PyMC experimental.
   :maxdepth: 2
 
 
+:mod:`pymc_experimental`
+=============================
+
+.. automodule:: pymc_experimental.marginal_model
+   :members: MarginalModel
+
+.. automodule:: pymc_experimental.model_builder
+   :members: ModelBuilder
+
+
+:mod:`pymc_experimental.inference`
+=============================
+
+.. automodule:: pymc_experimental.inference.fit
+   :members: fit
+
+
 :mod:`pymc_experimental.distributions`
 =============================
 
+.. automodule:: pymc_experimental.distributions.continuous
+   :members: GenExtreme
+
 .. automodule:: pymc_experimental.distributions.histogram_utils
    :members: histogram_approximation
 
 
+:mod:`pymc_experimental.gp`
+=============================
+
+.. automodule:: pymc_experimental.gp.latent_approx
+   :members: HSGP
+
+
 :mod:`pymc_experimental.utils`
 =============================
 
@@ -24,3 +51,4 @@ methods in the current release of PyMC experimental.
 
 .. automodule:: pymc_experimental.utils.prior
    :members: prior_from_idata
+