docs: #202 code block headings text are tiny on mobile

Author: thescientist13

docs/components/ctc-block/ctc-block.css

@@ -22,7 +22,7 @@
     background-color: var(--color-prism-bg);
     color: var(--color-white);
     padding: 10px;
-    font-size: var(--size-2);
+    font-size: var(--size-3);
     border-radius: var(--radius-2) var(--radius-2) 0 0;
     font-family: 'Geist-Mono', monospace;
     font-style: italic;