export accept_strict_improvement?

At the moment `accept_strict_improvement()` is marked as internal. This means that it's not exported and a user cannot read the documentation.

I propose to exporting it. @ingitwetrust what do you think?

Start by locating the definition of accept_strict_improvement() and the package's export declarations. Check how exported functions are documented, then make the function publicly accessible and verify that users can read its documentation.

Written by the indexing model from the issue text.