Issue 29: Update README workflow

[athowes]

Description

This PR will close issue #29.

So far, I have copied exactly the file https://github.com/epinowcast/epinowcast/blob/main/.github/workflows/render-readme.yaml from epinowcast to here.

I don't have a very good understanding of these .yaml workflow files yet, so @seabbs if you could give me some guidance on what to change here to get this working, that'd be great. (Happy to have a short call about it if easier!)

Ideally this would serve as a learning opportunity for me to be more confident to make these sorts of edits in future.

Checklist

• My PR is based on a package issue and I have explicitly linked it.
• I have included the target issue or issues in the PR title in the for Issue(s) issue-numbers: PR title
• I have read the contribution guidelines.
• I have tested my changes locally.
• I have added or updated unit tests where necessary.
• I have updated the documentation if required.
• My code follows the established coding standards.
• I have added a news item linked to this PR.
• I have reviewed CI checks for this PR and addressed them as far as I am able.

[seabbs]

This looks like it works as is to me