[PROPOSAL] [BREAKING CHANGE] change default project structure

[koba04]

Currently, create-plugin generates JS files based on ES5 and jQuery.
I think it's good for beginners, but it has many works to use TypeScript, webpack, and so on.

So I consider changing the default project structure using TypeScript and webpack.
Of course, the project supports IE11, so your plugin still works fine on IE11.

TypeScript gives us great developer experiences with VSCode, and webpack makes it easy to use npm packages like React and Vue.

I also consider providing the existing default project structure as an option like --legacy or --minimum.

[koba04]

I'm reconsidering adding this with an experimental flag to give feedback about the new project structure before making this the default structure.