[css-contain-1][editorial] Fixed Bikeshed issues

Author: SebastianZ

css-contain-1/Overview.bs

@@ -41,6 +41,7 @@ spec:css21; type:value; property: height; text:auto
 spec:css-sizing-4; type:property; text:aspect-ratio
 spec:css-sizing-3; type:value; for:width; text:min-content
 spec:css-sizing-3; type:value; for:width; text:max-content
+spec:html; type:element; text:body
 </pre>
 
 <h2 id='intro'>
@@ -615,7 +616,7 @@ Size Containment</h3>
 
 				<wpt>
 				contain-size-064.html
-				<wpt>
+				</wpt>
 		</dl>
 
 		Note: [=Size containment=] does not suppress baseline alignment.