Test moving images into folders with post content

[frankieroberto]

This is a test to explore whether it would be easier to move from having separate image and post folders like this:

/app/images/service-name/YYYY/MM/post-name/image-name.png
/app/posts/service-name/YYYY/MM/post-name.md

to having combined images-and-posts folders like this:

/app/service-name/YYYY/MM/post-name/index.md
/app/service-name/YYYY/MM/post-name/image-name.png

The main advantages would be:

• no need to make sure that the folder name in app/images exactly matches the post name, which is a common source of mistakes
• easier to create posts using the GitHub web interface, as currently there’s no way to create folders in which to upload images using the web interface without resorting to workarounds
• the Markdown previews in the GitHub web interface should show the embedded images

The disadvantages are:

• might be slightly slower, as the 'glob' file references mean that Eleventy has to scan all the folders for matching filenames

Fixes #153

[frankieroberto]

Here’s an example showing the images working within the GitHub Markdown preview: https://github.com/NHSDigital/prevention-services-design-history/blob/test-moving-images-into-folder-with-post/app/record-a-vaccination/2025/03/asking-fewer-better-questions/index.md

This clinches it for me, as the previews are really helpful for reviewing!

[frankieroberto]

Closing this test as I’ve re-done it in #235