feat: various markup improvements for semantic

src/css/blocks/posts.css

@@ -1,4 +1,4 @@
 .posts-list-item {
   display: grid;
-  grid-template-columns: 1fr auto;
+  grid-template-columns: auto auto;
 }

src/css/utilities/fonts.css

@@ -29,3 +29,7 @@
 .line-height-l {
   line-height: 1.5rem;
 }
+
+.line-height-xl {
+  line-height: 2rem;
+}