Refer to AbortController and BroadcastChannel as APIs

This is more in line with web-platform-dx#810,
although the discussion continues:
web-platform-dx#822

Author: foolip

feature-group-definitions/aborting.dist.yml

@@ -2,7 +2,7 @@
 # Do not edit this file by hand. Edit the source file instead!
 
 name: AbortController and AbortSignal
-description: The `AbortController` and `AbortSignal` interfaces allow you to cancel an ongoing operation, such as a `fetch()` request.
+description: The `AbortController` and `AbortSignal` APIs allow you to cancel an ongoing operation, such as a `fetch()` request.
 spec: https://dom.spec.whatwg.org/#aborting-ongoing-activities
 caniuse: abortcontroller
 status:

feature-group-definitions/aborting.yml

@@ -1,5 +1,5 @@
 name: AbortController and AbortSignal
-description: The `AbortController` and `AbortSignal` interfaces allow you to cancel an ongoing operation, such as a `fetch()` request.
+description: The `AbortController` and `AbortSignal` APIs allow you to cancel an ongoing operation, such as a `fetch()` request.
 spec: https://dom.spec.whatwg.org/#aborting-ongoing-activities
 caniuse: abortcontroller
 compat_features:

feature-group-definitions/broadcast-channel.yml

@@ -1,5 +1,5 @@
 name: BroadcastChannel
-description: The `BroadcastChannel` interface allows you to send messages between same-origin browsing contexts, such as between the same page loaded in multiple tabs.
+description: The `BroadcastChannel` API allows you to send messages between same-origin browsing contexts, such as between the same page loaded in multiple tabs.
 spec: https://html.spec.whatwg.org/multipage/web-messaging.html#broadcasting-to-other-browsing-contexts
 caniuse: broadcastchannel
 usage_stats: https://chromestatus.com/metrics/feature/timeline/popularity/1447