HTML folding range should include end tag

[AlexXuChen]

Currently, the VSCode HTML folding range doesn't include the end tag. Recently a change was made to XML Language Support by Red Hat to enclose the end tag:

This suggestion came at a request to improve readability and save screen space: eclipse-lemminx/lemminx#1178

It would be nice for the VSCode HTML language support to also include this in it's folding range.

If this is a suggestion you believe is important to add, I've already made a POC ready to pr.