Request: Include a link to this repo at the bottom of the docs page

[axelson]

I think that we could get more people to contribute doc improvements if at the bottom of the official docs page (e.g. pages like https://docs.atuin.sh/configuration/config/#sync_address) there was a blurb similar to "Contribute to these docs at https://github.com/atuinsh/docs/blob/main/src/content/docs/configuration/config.mdx")

Also it was a little harder finding these docs because the main atuin repo (https://github.com/atuinsh/atuin/) does have a docs/ folder, but it only includes non-english docs and doesn't link here.