Expose plot_gp_dist at package level (#4835)

* Expose `plot_gp_dist` at package level

This is a super useful helper function that works for many things beyond Gaussian processes.

* Mention plot_gp_dist API shortcut

* Run pre-commit

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: michaelosthege

RELEASE-NOTES.md

@@ -12,6 +12,7 @@
 ### New Features
 + Generalized BART, bounded distributions like Binomial and Poisson can now be used as likelihoods (see [#4675](https://github.com/pymc-devs/pymc3/pull/4675), [#4709](https://github.com/pymc-devs/pymc3/pull/4709) and
 [#4720](https://github.com/pymc-devs/pymc3/pull/4720)).
++ `plot_gp_dist` is now available at the package level: `pm.plot_gp_dist` ([see #4835](https://github.com/pymc-devs/pymc3/pull/4835)).
 
 ## PyMC3 3.11.2 (14 March 2021)
 

pymc3/__init__.py

@@ -88,6 +88,7 @@ def _hotfix_theano_printing():
 from pymc3.distributions import transforms
 from pymc3.exceptions import *
 from pymc3.glm import *
+from pymc3.gp.util import plot_gp_dist
 from pymc3.math import (
     expand_packed_triangular,
     invlogit,