Rewrite front js in vanilla - Fix #121

[corentin-gautier]

Hi @philbuchanan !

Thanks for this plugin ! I've been using it on a couple of projects already, however the dependency to jquery is kind of a deal breaker ... so I took the liberty to rewrite the js into vanilla !

I hope you'll be able to test this and merge if everything's ok 🎉

Rewrite front js in vanilla - Fix #121 add alignment support - Fix #103

accordion-blocks.min.js is now 1.8kB instead of 1.3kB (gzipped) but this removes ~37kB of jquery dependencies 🎉 .

EDIT :

• added support for hidden until-found (Fix #161)
• also removed the use of children, not sure this Fix #117 though
• Fix #59
• Fix #155
• Fix #173
• Close #151