docs: add a comment on the numpydoc docstring format style used when

documenting the code

docs/source/documentation.md

@@ -1,13 +1,19 @@
 # Documentation
 
-This project is documented using
+This project documentation is generated using
  [Sphinx](https://www.sphinx-doc.org)
 and
  [numpydoc](https://numpydoc.readthedocs.io).  
+The numpydoc formatting style as documented in the
+ [style guide](https://numpydoc.readthedocs.io/en/latest/format.html)
+is used. See the
+ [example](https://numpydoc.readthedocs.io/en/latest/example.html#example) in
+the numpydoc documentation on how to properly document the code.
+
 The theme being used is [Read the Docs Sphinx Theme](https://sphinx-rtd-theme.readthedocs.io).
 
 To generate the documentation (in HTML format, see `doc/Makefile` for other formats), execute:
 ```
 cd docs
 make html
-```
+```