Import content of a template as variable (client side)

I’d like to import statics contents stocked in different files in a folder on client side ('../static/'), in order to be able to regroup them, to modify them easily (even by others non-technicals marketing guys) when needed and to propagate their modification all over my app where they are used.

So my idea is to inject their content in var for using them where I need to (specially in js swal modals). I saw solutions on server side (Assets.getText, s.readdirSync) but I find this too heavy, making me writing methods just to inject some very basic html texts (<h1> <br> <b> <i>)…

Is there a client side only simple solution?