Update introduction section

This removes mention of Media Playback Quality, which isn't
in scope, and display capability detection is solved elsewhere

index.bs

@@ -140,43 +140,25 @@ spec: secure-contexts; urlPrefix: https://www.w3.org/TR/secure-contexts/
   <em>This section is non-normative</em>
 
   <p>
-    This specification relies on exposing the following sets of properties:
-    <ul>
-      <li>
-        <p>
-          An API to query the user agent with regards to the decoding and
-          encoding abilities of the device based on information such as the
-          codecs, profile, resolution, bitrates, etc. The API exposes
-          information such as whether the playback should be smooth and power
-          efficient.
-        </p>
-        <p>
-          The intent of the decoding capabilities API is to provide
-          a powerful replacement to APIs such as
-          {{MediaSource/isTypeSupported()}} or
-          {{HTMLMediaElement/canPlayType()}} which are vague and mostly help
-          callers know if something cannot be decoded but not how well it
-          should perform.
-        </p>
-      </li>
-      <li>
-        <p>
-          Better information about the display properties, such as supported
-          color gamut or dynamic range abilities, in order to pick the right
-          content for the display and to, for example, avoid providing HDR
-          content to an SDR display.
-        </p>
-      </li>
-      <li>
-        <p>
-          Real time feedback about the playback so an adaptative streaming can
-          alter the quality of the content based on actual user perceived
-          quality. Such information will allow websites to react to a pick of
-          CPU/GPU usage in real time. It is expected that this will be tackled
-          as part of the [[media-playback-quality]] specification.
-        </p>
-      </li>
-    </ul>
+    This specification defines an API to query the user agent with regards
+    to the audio and video decoding and encoding abilities of the device,
+    based on information such as the codecs, profile, resolution, bitrates,
+    etc., of the media. The API exposes information such as whether the
+    playback should be smooth and power efficient.
+  </p>
+  <p>
+    The intent of the decoding capabilities API is to provide a powerful
+    replacement for APIs such as {{MediaSource/isTypeSupported()}} or
+    {{HTMLMediaElement/canPlayType()}} which are vague and mostly help
+    callers know if something cannot be decoded but not how well it
+    should perform.
+  </p>
+  <p>
+    This specification focuses on encoding and decoding capabilities.
+    It is expected to be used with other web APIs that provide information about
+    the display properties, such as supported color gamut or dynamic range abilities,
+    to enable web applications to pick the right content for the display and to,
+    for example, avoid providing HDR content to an SDR display.
   </p>
 </section>