Add docstrings flake8 checks.

.flake8

@@ -3,3 +3,4 @@ max-line-length = 88
 extend-ignore = E203
 per-file-ignores =
     exploration/*.py:E501
+docstring-convention = numpy

config/environment.yml

@@ -6,6 +6,7 @@ dependencies:
   - black
   - isort
   - flake8
+  - flake8-docstrings
   - imbalanced-learn=0.10.0
   - jupyterlab
   - jupytext
@@ -15,6 +16,7 @@ dependencies:
   - pandas
   - psycopg2 >= 2.9.1
   - pre-commit
+  - pydocstyle
   - python-dotenv
   - pytz
   - pyprojroot