Feature: Data folder as data source

We are missing a useful source: Hugo data folder!

If we had a /data source, we could have a prebuild cache if we wanted one, for things like issues and readmes. I realise at some point we are essentially reinventing the database, so let's be minimal on this!

Things to consider:

1. Do we want to be data first or remote first for source?
1. ???

I would probably start by defining some folders in /data that match the block types and sources, like /github/readme github/issues /local . Then I would update the api value in blockData scratch.

Relevant chunk of code https://github.com/CodeYourFuture/curriculum/tree/main/common-theme/layouts/partials/block
https://common.codeyourfuture.io/common-theme/block-types/