Apply h5 and h6 styles to all content

This applies the `font-weight` values to all `h5` and `h6` elements, not
just those on pages with an `#enable-section-numbers` element.

Author: jonathanhefner

docs/style.css

@@ -1,3 +1,13 @@
+#content-area {
+  h5 {
+    font-weight: 500;
+  }
+
+  h6 {
+    font-weight: 400;
+  }
+}
+
 #feature-support-matrix-wrapper {
   overflow-x: auto;
 }
@@ -73,12 +83,4 @@ body:has(#enable-section-numbers) {
     content: counter(h2-counter) "." counter(h3-counter) "." counter(h4-counter)
       "." counter(h5-counter) "." counter(h6-counter) " ";
   }
-
-  #content-area h5 {
-    font-weight: 500;
-  }
-
-  #content-area h6 {
-    font-weight: 400;
-  }
 }