Add feature for interest invokers

Author: mfreed7

features/interest-invokers.yml

@@ -0,0 +1,7 @@
+name: 'Interest invokers'
+description: The `interestfor` global HTML attribute adds "interest" behaviors to the element, such that when the user "shows interest" in the element, actions are triggered on the target element, such as showing a popover. The user agent handles detecting when the user "shows interest" in the element, via methods such as hovering the element with a mouse, hitting special hotkeys on the keyboard, or long-pressing the element on touchscreens. When interest is shown or lost, an `InterestEvent` is fired on the target, which have default actions in the case of popovers - showing and hiding the popover.
+spec: https://github.com/whatwg/html/pull/11006
+group: html
+compat_features:
+  - api.HTMLElement.interestfor
+  - html.global_attributes.interestfor