Add support to Json files

[mjsmagalhaes]

Is your feature request related to a problem? Please describe.
JSON files are ignored by the building process.

Describe the solution you'd like.
To pack json files with HTML data (like tweego handles images, videos, captions ...)

Describe alternatives you've considered.
An alternative is to add the JSON file to a JS lib to import it or use a server to have the data download in execution time.

Additional context.
We have 3 solutions (that I can see) to solve JSON data availability: pack with html, pack with JS and download it during execution.

Serving data is best avoided because it requires some infrastructure and running a server during development.

Packing that with the JS isn't terrible but I believe we should avoid. The bundle may become large and js files will have to be downloaded again after each data update. It also requires either a building tool or a manual update. I am currently using this approach ... recompiling code after data update is a nuisance but solves it.

Packing with HTML is probably the best solution as it requires nothing extra from the author and keep the alternatives possible if anyone is interested.