Update deploy.yml

[kklamberty]

I think we need to update our deploy.yml file to include

permissions: contents: write

after the name: Deploy line. There seems to be a difference between the version we have been working on and what happens when we use that template. I can't see how to select read and write permissions (I'm prevented from doing so) in the settings>actions>general toward the bottom. However, adding these two lines to the .yml file make the check pass, so I think it's a good solution. I'm genuinely not sure if that will make it automatically able to create the gh-pages branch (which I did manually), but it seems important that write permissions are granted to the workflow.

[kklamberty]

I found the note to try this here: https://github.com/JamesIves/github-pages-deploy-action