added changelog and version dropdown

src/components/navigation/sidebars/nav/VersionSelector.astro

@@ -0,0 +1,48 @@
+---
+import fs from 'node:fs';
+import path from 'node:path';
+
+import Link from './Link.astro';
+import Accordion from "@components/Accordion.astro"
+
+interface Props {
+  title: string;
+  link: string;
+  current?: boolean;
+}
+interface VersionData {
+  default: string;
+  versions: {
+    name: string;
+    types: string;
+  }[]
+}
+const versionFilePath = import.meta.env.VERSION_FILE_PATH;
+
+if (!versionFilePath){
+  throw new Error("no env var VERSION_FILE_PATH")
+}
+const absolutePath = path.resolve(process.cwd(), versionFilePath);
+const versionData:VersionData = JSON.parse(fs.readFileSync(absolutePath, 'utf-8'));
+
+const { title, link, current } = Astro.props;
+---
+<Accordion class=`nav-component version-collapsible ${current ? "nav-current" : ""}` {...(!current ? { open: "_" } : {})}>
+  <div slot="header">
+    <span class="nav-component nav-item nav-link">
+      versions
+    </span>
+  </div>
+  <div class="version-select-menu">
+    {versionData.versions.map((ver, _) => {
+      return (
+        <Link
+          link={`${Astro.url.pathname}`}
+          title=`${ver.name}`
+        >
+          {ver.name}
+        </Link>
+      )}
+    )}
+  </div>
+</Accordion>