[BUG] Fails to recognize README on some repos

[cmgriffing]

Describe the bug
Stethoscope fails to recognize the README file sometimes. It will show a score which means it was found in some way, but the checklist shows "does not exist".

example repo:
https://github.com/plotly/plotly.js

[uncenter]

Seeing this fail on my https://github.com/catppuccin/github-file-explorer-icons repository as well. Might want to look into using https://docs.github.com/en/rest/repos/contents?apiVersion=2022-11-28#get-a-repository-readme to let GitHub do the README detecting for you? 404s if there isn't one, returns the size and content in JSON if there is one.