feat(docs): integrate ReadTheDocs version selector

- Add JavaScript for ReadTheDocs version menu integration
- Switch from external CDN to self-hosted JS file
- Improves documentation navigation and reliability

Author: liblaf

docs/javascript/readthedocs.js

@@ -0,0 +1,44 @@
+// ref: <https://docs.readthedocs.com/platform/stable/intro/mkdocs.html#integrate-the-read-the-docs-version-menu-into-your-site-navigation>
+
+document.addEventListener("DOMContentLoaded", function (event) {
+  // Trigger Read the Docs' search addon instead of Material MkDocs default
+  document.querySelector(".md-search__input").addEventListener("focus", (e) => {
+    const event = new CustomEvent("readthedocs-search-show");
+    document.dispatchEvent(event);
+  });
+});
+
+// Use CustomEvent to generate the version selector
+document.addEventListener("readthedocs-addons-data-ready", function (event) {
+  const config = event.detail.data();
+  const versioning = `
+<div class="md-version">
+<button class="md-version__current" aria-label="Select version">
+    ${config.versions.current.slug}
+</button>
+
+<ul class="md-version__list">
+${config.versions.active
+  .map(
+    (version) => `
+    <li class="md-version__item">
+    <a href="${version.urls.documentation}" class="md-version__link">
+        ${version.slug}
+    </a>
+            </li>`,
+  )
+  .join("\n")}
+</ul>
+</div>`;
+
+  // Check if we already added versions and remove them if so.
+  // This happens when using the "Instant loading" feature.
+  // See https://squidfunk.github.io/mkdocs-material/setup/setting-up-navigation/#instant-loading
+  const currentVersions = document.querySelector(".md-version");
+  if (currentVersions !== null) {
+    currentVersions.remove();
+  }
+  document
+    .querySelector(".md-header__topic")
+    .insertAdjacentHTML("beforeend", versioning);
+});

template/.config/copier/mkdocs.yaml.jinja

@@ -22,7 +22,7 @@ extra_css:
 
 extra_javascript:
   - https://cdn.jsdelivr.net/gh/liblaf/copier-python/docs/javascript/mathjax.min.js
-  - https://cdn.jsdelivr.net/gh/readthedocs/test-builds@mkdocs-material/docs/javascripts/readthedocs.min.js
+  - https://cdn.jsdelivr.net/gh/liblaf/copier-python/docs/javascript/readthedocs.min.js
   - https://unpkg.com/mathjax@3/es5/tex-mml-chtml.js
 
 theme: