styling: Increase font size for headings

- Increase the heading sizes to more reasonable values.
- Change the color of the `h5` heading from light to dark gray

Signed-off-by: jaydee-coder <[email protected]>

Author: jaydee-coder

docs/stylesheets/extra.css

@@ -5,4 +5,19 @@
   --md-accent-fg-color:          #D3506F;
   --md-footer-bg-color:          #2C2C2C;
   --md-footer-bg-color--dark:    #2C2C2C;
+  --md-default-fg-color--light:  #000000B0;
 }
+
+/* Heading overrides as the default ones are very small */
+.md-typeset {
+  h4 {
+    font-size: 0.95rem;
+  }
+  h5 {
+    font-size: 0.8rem;
+  }
+  h6 {
+    font-size: 0.7rem;
+  }
+}
+