add "descriptive narration" to bring in WCAG definition's alternate names

Author: maryjom

comments-by-guideline-and-success-criterion.md

@@ -71,7 +71,7 @@ The WCAG 2 definition of “[audio description](https://www.w3.org/TR/WCAG22/#df
 Secondary or alternate audio tracks are commonly used for this purpose.</div>
 <div class="note wcag2ict">
 
-Audio descriptions (also called "video descriptions" and "described videos") add descriptive information of important visual information needed to understand the video content, including text displayed in the video. Where the main audio track of the video fully describes important visual information, audio descriptions would not be needed at all as the requirement would already be met. When audio descriptions are needed, one way to implement them is by providing a second audio track for the audio-video media.</div>
+Audio descriptions (also called "video descriptions", "descriptive narration", and "described videos") add descriptive information of important visual information needed to understand the video content, including text displayed in the video. Where the main audio track of the video fully describes important visual information, audio descriptions would not be needed at all as the requirement would already be met. When audio descriptions are needed, one way to implement them is by providing a second audio track for the audio-video media.</div>
 
 <div class="note wcag2ict software">