"Visual" tool to help preparing submissions

[avivace]

It should provide a way to generate a folder ready to be submitted in this repository, containing all the game data properly tagged and the game.json (shoul be visually editable on a form generated from the JSON Schema)

[avivace]

I have an experimental Google form which also accepts file uploads, still need to write down a simple script converting the submissions to proper manifests

[dag7dev]

since form response could be saved as a csv it should be easy. This would close #231 too.