Backward compat for GrapesJS apps and Silex

I built a plugin that alerts users when the app changed, runs upgrade steps, and shows a modal with progress and changelog

I will add it to Silex soon

• Demo: https://codepen.io/lexoyo/full/JoYMqZJ
• Code: https://github.com/silexlabs/grapesjs-version-flow

What do you think?