Merge branch 'doc_additions' into 'master'

docs/_static/css/custom_list_styling.css

docs/_static/css/dark.css

docs/_static/images/cc_by_v4_size88x31.png

docs/_themes/sphinx_rtd_theme/Apache-License-2.0.txt

docs/_themes/sphinx_rtd_theme/LICENSE

docs/_themes/sphinx_rtd_theme/OFL-License.txt

docs/_themes/sphinx_rtd_theme/__init__.py

docs/_themes/sphinx_rtd_theme/breadcrumbs.html

docs/_themes/sphinx_rtd_theme/footer.html

docs/_themes/sphinx_rtd_theme/layout.html

.../_themes/sphinx_rtd_theme/locale/de/LC_MESSAGES/sphinx.mo

.../_themes/sphinx_rtd_theme/locale/de/LC_MESSAGES/sphinx.po

.../_themes/sphinx_rtd_theme/locale/en/LC_MESSAGES/sphinx.mo

.../_themes/sphinx_rtd_theme/locale/en/LC_MESSAGES/sphinx.po

.../_themes/sphinx_rtd_theme/locale/es/LC_MESSAGES/sphinx.mo

.../_themes/sphinx_rtd_theme/locale/es/LC_MESSAGES/sphinx.po

.../_themes/sphinx_rtd_theme/locale/et/LC_MESSAGES/sphinx.mo

.../_themes/sphinx_rtd_theme/locale/et/LC_MESSAGES/sphinx.po

.../_themes/sphinx_rtd_theme/locale/fr/LC_MESSAGES/sphinx.mo

.../_themes/sphinx_rtd_theme/locale/fr/LC_MESSAGES/sphinx.po