Added the AVIF format to the list of core media types (#2811)

* Added the AVIF format

* Images -> images

Author: iherman

epub34/authoring/index.html

@@ -1002,26 +1002,33 @@ <h3>Core media types</h3>
 						<tr>
 							<th colspan="3" id="cmt-grp-image" class="tbl-group">Images</th>
 						</tr>
+						<tr>
+							<td id="cmt-avif" data-tests="#pub-cmt-avif">
+								<code>image/avif</code>
+							</td>
+							<td> [[av1-avif]] </td>
+							<td>AVIF images</td>
+						</tr>
 						<tr>
 							<td id="cmt-gif" data-tests="#pub-cmt-gif">
 								<code>image/gif</code>
 							</td>
 							<td> [[gif]] </td>
-							<td>GIF Images</td>
+							<td>GIF images</td>
 						</tr>
 						<tr>
 							<td id="cmt-jpeg" data-tests="#pub-cmt-jpeg">
 								<code>image/jpeg</code>
 							</td>
 							<td> [[jpeg]] </td>
-							<td>JPEG Images</td>
+							<td>JPEG images</td>
 						</tr>
 						<tr>
 							<td id="cmt-png" data-tests="#pub-cmt-png">
 								<code>image/png</code>
 							</td>
 							<td> [[png]] </td>
-							<td>PNG Images</td>
+							<td>PNG images</td>
 						</tr>
 						<tr>
 							<td id="cmt-svg" data-tests="#pub-cmt-svg,#cnt-svg-support">
@@ -1037,7 +1044,7 @@ <h3>Core media types</h3>
 								<code>image/webp</code>
 							</td>
 							<td> [[rfc9649]] </td>
-							<td>WebP Images</td>
+							<td>WebP images</td>
 						</tr>
 						<tr>
 							<th colspan="3" id="cmt-grp-audio" class="tbl-group">Audio</th>
@@ -12019,6 +12026,8 @@ <h2>Change log</h2>
 			<details id="changes-epub-33" open="open">
 				<summary>Substantive changes since <a href="https://www.w3.org/TR/epub-33/">EPUB 3.3</a></summary>
 				<ul>
+					<li>06-October-2025: Added AVIF as a core media type for images. See 
+						<a href="https://github.com/w3c/epub-specs/issues/2794">issue 2794</a>.</li>
 					<li>26-June-2025: Moved the <code>xsd</code>, <code>msv</code>, and <code>prism</code> reserved
 						prefixes to the deprecated features section. See <a
 							href="https://github.com/w3c/epub-specs/issues/2739">issue 2739</a>.</li>

epub34/rs/index.html

@@ -308,7 +308,7 @@ <h3>Publication resource processing</h3>
 				<h4>Core Media types</h4>
 
 				<p id="confreq-rs-epub3-images"
-					data-tests="#pub-cmt-gif,#pub-cmt-jpg,#pub-cmt-png,#pub-cmt-svg,#pub-cmt-webp">If a reading system
+					data-tests="#pub-cmt-avif,#pub-cmt-gif,#pub-cmt-jpg,#pub-cmt-png,#pub-cmt-svg,#pub-cmt-webp">If a reading system
 					has a [=viewport=], it MUST support the <a data-cite="epub-34#cmt-grp-image">image core media type
 						resources</a> [[epub-34]].</p>