feat: rework module using react native bob

[vonovak]

Summary

this PR reworks the module to be built on top of react native builder bob which provides some cool benefits out of the box:

• there is an example project linked to the the module sources, the example project can be used to develop the module itself: this is something immensely helpful for making contributions easier to happen
• releases will be done automatically, including release notes
• TS typings are no longer maintained separately - the module JS part was rewritten to TS

closes #343

Test Plan

Example project runs on android and ios device

should run on windows as well: @qmatteoq could you please double check this works fine on windows and add example project that could be used for development? Perhaps datetime picker repo could be of help: https://github.com/react-native-datetimepicker/datetimepicker/tree/master/example

What are the steps to reproduce (after prerequisites)?

see contributing.md

Compatibility

OS	Implemented
iOS	✅
Android	✅
Windows	?

Checklist

• I have tested this on a device and a simulator
• I added the documentation in README.md
• I updated the typed files (TS and Flow)

[qmatteoq]

I confirm everything keeps working fine on Windows. In the next days I will work on a Windows sample to add to the existing ones and I'll submit a PR.

[vonovak]

@qmatteoq perfect, thank you!

There's one more thing: this PR #380 added a folder picker windows-only functionality to the library but was never documented. In a recent PR, the same functionality was added on Android #414, under the pickDirectory name.

Would you be so kind and rework the old, undocumented implementation so that pickDirectory works on windows as well? I believe it should not be too complicated :)

Also, what do you think of the naming? Would you prefer this to be named pickDirectory or selectDirectory or does it not matter in your opinion? Thanks again :)

btw I'll be vacationing now for 10 days so I won't respond here :)

[qmatteoq]

The way I implemented this feature in Windows is to retrieve a list of all the files in the selected folder, but I realize that this is different from what you have in the other platforms. I will rework the feature to work like on Android and return the path of the selected folder and submit a PR. Enjoy your holidays! 😊

[qmatteoq]

Also, what do you think of the naming? Would you prefer this to be named pickDirectory or selectDirectory or does it not matter in your opinion? Thanks again :)

I like pickDirectory more, since it's consistent with the existing APIs for files ☺

[vonovak]

so, the PR is now complete. I will find some time later this week to merge this and set up automated publishing.