IE11 Support

[C1rdec]

I know that IE 11 is no more supported by Microsoft but many legacy system or still using IE11.

• Example : Winform WebView

We were using inter-cooler and we decided to migrate to htmx and I was pleased to see that htmx was compatible with IE11.

But since 1.7.0 there's 2 breaking change for IE11....

We manage to make it work with 2 small changes:

1. Use a function here
2. GetRootNode