Update time-based-media.html

fixes #4341 by addressing minor typos

Author: mbgower

understanding/20/time-based-media.html

@@ -14,7 +14,7 @@ <h2>Intent of Time-Based Media</h2>
 
 
       <p>The purpose of this guideline is to provide access to time-based and synchronized
-         media.This includes media that is:
+         media. This includes media that is:
       </p>
 
       <ul>
@@ -36,9 +36,7 @@ <h2>Intent of Time-Based Media</h2>
 
       <p>For 
          <strong>audio-only</strong> or 
-         <strong>video-only</strong> media, you only need to apply the success criteria that say "
-         <strong>audio-only</strong>" or "
-         <strong>video-only</strong>" in their short name. If your media is not 
+         <strong>video-only</strong> media, you only need to apply the success criteria that say "<strong>audio-only</strong>" or "<strong>video-only</strong>" in their short name. If your media is not 
          <strong>audio-only</strong> or 
          <strong>video-only</strong>, then all the rest of the success criteria apply.
       </p>