Update HEVC support status for Firefox (#38395)

Co-authored-by: Chris Mills <[email protected]>

Author: wbsdty331

files/en-us/web/media/guides/formats/video_codecs/index.md

@@ -1038,7 +1038,7 @@ HEVC is a proprietary format and is covered by a number of patents. Licensing is
               <th scope="row">HEVC / H.265 support</th>
               <td>107</td>
               <td>18</td>
-              <td>No</td>
+              <td>120</td>
               <td>94</td>
               <td>11</td>
             </tr>
@@ -1049,7 +1049,7 @@ HEVC is a proprietary format and is covered by a number of patents. Licensing is
           <a href="https://apps.microsoft.com/detail/9nmzlz57r3t7">HEVC video extensions from the Microsoft Store</a>
           is installed, and has the same support status as Chrome on other platforms. Edge (Legacy) only supports HEVC for devices with a hardware decoder.
         </p>
-        <p>Mozilla will not support HEVC while it is encumbered by patents.</p>
+        <p>Firefox 120 initially supported HEVC decoding in Nightly only. Support was enabled by default in Firefox 134 on Windows, Windows and macOS in Firefox 136, and Windows, macOS, and Linux in Firefox 137. HEVC support is provided only on devices with hardware support (the range is the same as Edge).</p>
         <p>Opera and other Chromium based browsers have the same support status as Chrome.</p>
         <p>Safari supports HEVC for all devices on macOS High Sierra or later.</p>
       </td>