Add vanilla JS support

[nicocedron]

[pedrofurtado]

Some other implementation for reference: https://github.com/oddcamp/cocoon-vanilla-js

We are using this repo as "Cocoon vanilla js" for a while 👍

[OtherCroissant]

Why is the Rails gem not migrating to the vanilla JS version of @pedrofurtado ? Rails ujs has dropped the JQuery JS dependency for quite some time now...

[simi]

There are alternatives like https://github.com/arielj/vanilla-nested as well. Cocoon is just one solution for the problem based on jQuery and heavily opinionated (at least in my :eyes:).

[nathanvda]

Definitely opinionated, imho you can use any js you like (but I only maintain one version), but the vanilla-nested is looking pretty good indeed 👍 Lately not having as much time to keep up, and for my situation everything is working.