Add option section in setup.cfg

- [options] This section provides additional options for Setuptools package builds.
- [options].package_dir This is a list of key, value pairs to map discovered direct
                        ories to import paths. An empty key means the "root,"  such
                        that  any directory mapped to the root will be removed from
                        the import path and only its child directories will be incl
                        uded.
- [options].packages    This is either an explicit list of packages, or the special
                        find: directive that tells Setuptools to recursively search
                        for any packages. is often the find: best choice, as you wo
			n’t need to update it if you add new packages later.
[options.packages.find] This section provides options to the Setuptools package dis
			covery process triggered by the directive. find:
[options.packages.find].where This tells Setuptools which directory to look in  for
			       packages.

setup.cfg

@@ -10,3 +10,10 @@ long_description_content_type = text/markdown
 license = MIT
 license_files = LICENSE
 classifiers = License :: OSI Approved :: MIT License
+[options]
+package_dir =
+ =src
+packages = find:
+[options.packages.find]
+where = src
+