add sphinx classifiers

Author: Chilipp

pyproject.toml

@@ -18,6 +18,8 @@ classifiers = [
     'Intended Audience :: Developers',
     'Topic :: Documentation',
     'License :: OSI Approved :: Apache Software License',
+    'Framework :: Sphinx',
+    'Framework :: Sphinx :: Extension',
     'Programming Language :: Python :: 3',
     'Programming Language :: Python :: 3 :: Only',
     'Programming Language :: Python :: 3.7',