Provide format script

[Shinigami92]

This adds a format script to package.json's scripts block, so you can run npm run format and all supported files in the project will be formatted.

Folders like dist needs to be excluded because they are auto-generated.

The both other ignored files have a strange semicolon before the first brace in front of the async, so I just ignored these both files for now.

[goce-cz]

First of all, thank you for your contribution, it is very appreciated.

I left a single comment which resonates with my general approach to code-formating and linting:

If you think that rules are useful and important, define them well and then follow them. If you constantly need to break them, it's either because the rules are wrong or because you're to sloppy.

IMO this particular case fits more into the second category. Immediately executed anonymous functions are not something you use on a daily basis, so having a bit more verbose version won't kill anybody.

[littlewhywhat]

LGTM 🚀