Should simplesearch be compatible with IE11/older versions of Edge?

Hi,

We've run into an issue when using the simplesearch plugin on IE11 and older versions of Edge: these browsers don't support foreach on a NodeList (as employed [here](https://github.com/getgrav/grav-plugin-simplesearch/blob/1e381a79912987693fca3f551a18d3a0f7b229f6/js/simplesearch.js#L8)). Moreover, it seems that this means that all of our js doesn't load on these browsers if we choose to pipeline the js.

Are these browsers meant to be supported by this plugin (or is there another strategy we should be employing to address the lack of support)?