Scope image.scss styles to markdown-body, fix emoji rendering (github#20805)

Author: mikesurowiec

stylesheets/images.scss

@@ -1,12 +1,12 @@
-.procedural-image-wrapper {
+.markdown-body .procedural-image-wrapper {
   display: block;
   padding: 10px 0;
   margin: 20px auto 0 auto;
   border: none;
   max-width: calc(100% - 32px);
 }
 
-.procedural-image-wrapper img {
+.markdown-body .procedural-image-wrapper img {
   border-radius: 5px;
   border: 2px solid var(--color-auto-gray-2);
   width: auto;
@@ -16,11 +16,10 @@
 }
 
 // make sure images that contain emoji render at the expected size
-img[src*="https://github.githubassets.com/images/icons/emoji"]
+.markdown-body img[src*="https://github.githubassets.com/images/icons/emoji"]
 {
-  height: 20;
-  width: 20;
-  align: absmiddle;
+  height: 20px;
+  width: 20px;
 }
 
 .markdown-body img {