Support <a> tag for close button?

[ysds]

The _close.scss contains .disabled class and text-decoration: none; and etc, it seems that close buttons support <a>.

bootstrap/scss/_close.scss

Lines 10 to 16 in 283ab30

	&:not(:disabled):not(.disabled) {
	@include hover-focus {
	color: $close-color;
	text-decoration: none;
	opacity: .75;
	}

However, there is no document or demo about <a> anywhere. Also the style of disabled close button issue will be fixed in v4.1.2 (#26654), it works well with <button>, but does not work with <a>. Demo: https://codepen.io/anon/pen/KBwaLv

If Bootstrap don't support a close button with <a>, we can clean up that CSS.

[ysds]

Closing this issue, I missed the next description in the .close.scss.

// If you want the anchor version, it requires href="#".

However, I have created #26899 for fix an issue of disabled <a>.