Gracefully skip github info requests when the token has not been set

[eternoendless]

Questions	Answers
Description?	This change makes it so that when the access token environment variable has not been set, it will skip github requests and issue a warning (which makes for faster rendering when run locally). I've also moved the footer to a partial of its own and improved the code a little.
Type?	improvement
Sponsor company	PrestaShop SA

[matks]

Feel free to merge whenever ready for docs deploy 👍

[eternoendless]

Thanks for the review!