Add View Transitions to masthead images

Author: csswizardry

_includes/header--masthead.html

@@ -11,7 +11,7 @@
 
 {% include ribbon.html %}
 
-<header class="page-head  page-head--masthead" elementtiming=masthead>
+<header class="page-head  page-head--masthead" elementtiming=masthead style="view-transition-name: masthead;">
 
     <div class=wrapper>
 

_includes/sub-content.html

@@ -10,7 +10,7 @@
        alt
        width=720
        height=480
-       style="background-image: url(/img/css/masthead-small-lqip.jpg), url({% include base64/masthead.jpg.html %});"
+       style="background-image: url(/img/css/masthead-small-lqip.jpg), url({% include base64/masthead.jpg.html %}); view-transition-name: masthead;"
        elementtiming=sidebar-image
        decoding=sync>
 </p>