Migrate library to TypeScript

[mechamobau]

This Pull Request has been created to migrate the library to the TypeScript language. So, a few things have changed, but keeping all functionality of the lib:

• Some @types/* dependencies have been added inside devDependencies;
• Webpack now transpile TypeScript files and move type declaration files (*.d.ts) inside of dist/ on build script;
• Creates Prettier config file to keep future contribution according to the same expected format;

I've made this change only for study reasons, but I'm opening this PR to know if this can help the library.

[mechamobau]

@vmarchesin All tests passing and build working according to the expected. If you see another wrong thing, please tell me that I'll fix it ;)

[vmarchesin]

I tested it and it seems to be working as expected. I wasn't planning on updating this to TS but since you already went through the trouble of doing it it looks good. I'll publish a new version soon.

Thank you for the contribution :)

[vmarchesin]

Version 2.2.0 is released. I made some minor changes and added a very useful render optimisation that I forgot to put in place when I first created the package. The example folder should be up to date as well. Thanks again, everything seems to be in place.