Local/demo development json files

[flanksaul]

Also TBD: Add Netlify deployment with demo data

Issue from comment: "For local development can we move these into local json files directly so that we can get enable preview environments? e.g. https://github.com/flanksource/karina-ui/blob/master/src/App.vue#L60"

Originally posted by @moshloop in #22 (comment)