Fix broken themes link and make reference parameters searchable (#9)

* Initial plan

* Fix broken themes link and make reference doc params searchable via h3 headings

Co-authored-by: OrangeX4 <34951714+OrangeX4@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: OrangeX4 <34951714+OrangeX4@users.noreply.github.com>

Author: Copilot

scripts/generate-docs.py

@@ -702,7 +702,7 @@ def definition_to_mdx(defn: dict, source_file: str, github_base: str = GITHUB_SR
                 default_part = ""
 
             lines.append(
-                f"#### {display_name}{type_part}"
+                f"### {display_name}{type_part}"
                 f"{default_part} {{#{anchor_id}}}"
             )
             lines.append("")

src/pages/themes.js

@@ -88,7 +88,7 @@ export default function ThemesPage() {
             <Heading as="h1">Themes</Heading>
             <p className={styles.themesSubtitle}>
               Choose from six professionally designed themes — or{' '}
-              <Link to="/docs/build-your-own-theme">build your own</Link>.
+              <Link to="/docs/tutorials/build-your-own-theme">build your own</Link>.
             </p>
           </div>
         </div>