Partially reorganize styles into functional chunks, rather than by component

Move link, generic page layout, post list, and a bunch of leftover stuff in root.css to functional stylesheets in styles/root/.

assets/styles/root/099_utility.css

@@ -1,11 +1,13 @@
 @layer utility {
     .centered { text-align: center; }
+    
     .float-right {
         float: right;
         justify-self: end;
     }
 
     .nobreak { white-space: nowrap; }
+
     .noselect {
         cursor: default;
         -webkit-user-select: none;
@@ -26,4 +28,10 @@
     .visible { visibility: visible; }
 
     article.two-column { columns: 2; }
+
+    img.circular {
+      shape-outside: circle(50%);
+      -webkit-clip-path: circle(50%);
+      clip-path: circle(50%);
+    }
 }