Help/About: Final 5.2 about page updates.

Use final image URLs and fix a bug in IE11 where images were being cut off.

Props afercia, SergeyBiryukov, ianbelanger, desrosj, audrasjb.
See #46901.
Built from https://develop.svn.wordpress.org/trunk@45287


git-svn-id: http://core.svn.wordpress.org/trunk@45096 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/css/about.css

@@ -52,7 +52,7 @@
 
 .about-wrap .inline-svg img {
 	max-width: 100%;
-	width: 100%;
+	width: auto;
 	height: auto;
 }
 
@@ -343,6 +343,7 @@
 
 .about-wrap .headline-feature img {
 	max-width: 600px;
+	width: 100%;
 }
 
 /* Return to Dashboard Home link */