💡Add generics to OutputBlockData

[hata6502]

1. Describe a problem.
   By using Generics, Editor.js users can describe string literal types.

https://www.typescriptlang.org/docs/handbook/literal-types.html#string-literal-types

By using string literal types in OutputBlockData['type'], Editor.js users can describe more type-safe OutputData in each application.

2. Describe the solution you'd like. Mockups are welcome.
   See:
   https://github.com/hata6502/editorjs-examples/blob/main/examples/ExampleEditorJSData.ts#L17