Compatibility

[ryuran]

This plugin is tested against the following browsers:
Internet Explorer 9 and higher
…

This plugin use modern javascript syntaxe not compatible with IE: https://caniuse.com/#feat=es6-class
Maybe we should mention how to deal with it with babel.
Or provide a dist file covering this scope out of the box.

[enwin]

That mention is something we missed in the README file but we have it on the demo website: https://a11y.switch.paris/onglet.html

We might consider generating a legacy version of the script for users who wants to import the script directly from a web page instead of bundling it.