Remove polyfills from the library

[probil]

Currently library includes polyfill for built-ins like Promise, Symbol or Object.assign.

But according to the Vue CLI docs:

When using Vue CLI to build a library or Web Components, it is recommended to pass useBuiltIns: false to @vue/babel-preset-app to disable automatic polyfill injection. This ensures you don't include unnecessary polyfills in your code, as it should be the responsibility of the consuming app to include polyfills.

We can cut up to 50% of the library by removing those polyfills

TODO:

• PR perf(lib): remove built-in polyfills from the library #18
• Remove polyfills
• Describe needed polyfills in docs
• Release (v1.1.0)

[probil]

Implemented in #18 - v1.1.0