Remove duplicated documentation in component README files

[anandamaryon1]

What is the issue?

Each component includes a README file which includes example markup and the Nunjucks macros.

These are duplicated on the service manual design system pages for each component. This creates a maintenance burden and increases the risk of misalignment of the docs.

Suggestion

Remove the example markup and replace with a link to the component documentation within the service manual.

[edwardhorsford]

They also both document in slightly different ways, so you can't just copy and paste I think. Agree this is annoying!

[frankieroberto]

I think this would be relatively quick and easy to do – we’d just replace each README with a generic template like this one, which only differs by where it links to: https://github.com/alphagov/govuk-frontend/blob/main/packages/govuk-frontend/src/govuk/components/breadcrumbs/README.md

However might be worth thinking about best timing for this, as it’ll cause some conflicts with any work in progress? ie do we want to do it for the next breaking change release or not?