DOC: Updates to contribution guide

Updates to the contribution guide in preparation for the hack session.

Principal changes are the addition of ## Unit Testing, and modifications to the description of commit messages to reflect adoption of scipy standard

docs/conf.py

@@ -66,6 +66,7 @@ extensions = [
     'sphinx.ext.autosectionlabel',
     'sphinx_tabs.tabs',
     "sphinx.ext.linkcode",
+    'myst_parser'
 ]
 autosummary_generate = True