Feature: Set up GitHub Pages MVP

[ALRubinger]

Would be good for projects to have a good starting point for a project site. We can start small. There's also an effort we're looking at across Block to identify what that starting point may be - across DX, DevRel, Creative Studios, and OSPO teams.

But let's start small. @myronmarston has a great example we can leverage from ElasticGraph:

https://github.com/block/elasticgraph/blob/main/.github/workflows/publish-site.yaml