BREAKING CHANGE: deprecate `.markdown-body` used as `.prose`

src/scss/_partial/container.scss

@@ -1,12 +1,6 @@
-%container {
+@mixin container {
   max-width: fit-content;
   font-size: 1rem;
   color: var(--xm-c-general);
   line-height: 1.75;
-  > :first-child {
-    margin-top: 0;
-  }
-  > :last-child {
-    margin-bottom: 0;
-  }
 }

src/scss/prose.scss

@@ -1,8 +1,7 @@
 @use '_partial/container' as *;
 
-.markdown-body,
 .prose {
-  @extend %container;
+  @include container;
   @import '_partial/title';
   @import '_partial/text';
   @import '_partial/link';