Switch back to REST API for getting repo contents

[caleb15]

GraphQL requires a github token but REST API does not, assuming that you don't spam the API. I used graphql because I thought I just wanted the filename and the REST API provided a bunch of other info. In hindsight it was not worth the extra development time getting graphql working and the (admittedly small) burden upon the user to supply to the token. Also it turns out I needed the type as well to make sure I didn't accidentily match a folder named "CHANGES".

Ex: https://api.github.com/repos/celery/celery/contents/
docs: https://docs.github.com/en/rest/reference/repos#contents
Stackoverflow: https://stackoverflow.com/questions/38449371/github-api-check-if-a-file-exists-and-then-get-it-if-it-does