* corrections to docstring of weisfeiler_lehman_subgraph_hashes

* Update networkx/algorithms/graph_hashing.py

Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>

---------

Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>

* weisfeiler lehman subgraph hashing

* address PR comments: restructure tests and improvements to hashing logic

* slight speedup initialising node attribute labels

* docstring changes based on pr comments

* improved subgraph description and fixed a bug where edge directions are disregarded for isomorphism.
 Added tests for this case

* Added warning on hash changes to release_dev.rst

* Touch up release note.

* Fix sphinx warning about underline lengths.

Co-authored-by: Aaron Zolnai Lucas <aaronzolnailucas@quantexa.com>
Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>

* rst double colons for example code

* add nx. prefix to doctest function calls

* Remove one line from 1->2 migration rst file

the line shows code that works for 1.x *and* 2.x.
But it no longer works for all v2.x code.  Readers should just use the
next line of code, so no reason to keep this in the file.

* capture output from subplot and rename DiGraph as DG in introduction.rst

* skip running the entire test suite as an example in old_release_log.rst

* doctest of examples

* remove changes to nexp files

* Setup for numpydoc.
 * Add to doc requirements.
 * Replace napoleon with numpydoc in conf.py.

* DOC: Fixups from numpydoc.

* Format code w/ black

* Format docstrings w/ black

* Manual cleanup

* Tell pytest to ignore planned deprecations

* Don't call plt.show during testing

* Another known deprecation

* DOC: rm duplicate line from docstring example

* Minor cleanup

Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>

Co-authored-by: Dan Schult <dschult@colgate.edu>

Adds graph_hashing module containing the Weisfeiler Lehman
algorithm for hashing graphs.

Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>