fix(content-section): add <kbd> style

Like yari, but:
- Regular font size, not smaller.
- Thinner border, for consistency.

Author: caugner

components/content-section/server.css

@@ -117,11 +117,21 @@
     }
   }
 
-  code {
+  code,
+  kbd {
     padding: 0.125em 0.25em;
     border-radius: 0.25em;
   }
 
+  kbd {
+    font-family: var(--font-family-code);
+
+    color: var(--color-text-secondary);
+
+    background-color: var(--color-background-page);
+    border: 1px solid var(--color-border-primary);
+  }
+
   img {
     display: block;