docs: switch to Typescript for Astro config, update config for @astrojs/starlight 0.33.0

Upstream broke compatibility. It's easier to fix this kind of thing if
we're using Typescript, so switch.

Author: iainlane

docs/astro.config.mjs renamed to docs/astro.config.ts

@@ -7,7 +7,7 @@ const isLocalPreview = process.env.npm_lifecycle_script === 'astro dev';
 // https://astro.build/config
 export default defineConfig({
   site: 'https://tanka.dev',
-  base: process.env.PATH_PREFIX,
+  base: process.env.PATH_PREFIX ?? '/',
   trailingSlash: 'always',
   integrations: [
     starlight({
@@ -27,9 +27,11 @@ export default defineConfig({
       title: 'Grafana Tanka',
       description:
         'Grafana Tanka is the robust configuration utility for your Kubernetes cluster, powered by the Jsonnet language.',
-      social: {
-        github: 'https://github.com/grafana/tanka',
-      },
+      social: [{
+        icon: "github",
+        label: "github",
+        href: 'https://github.com/grafana/tanka',
+      }],
       logo: {
         src: './img/logo.svg',
         alt: 'Grafana Tanka logo',

docs/package.json

@@ -20,6 +20,7 @@
     "typescript": "^5.8.3"
   },
   "devDependencies": {
+    "@types/node": "^22.14.1",
     "prettier": "^3.5.3"
   },
   "packageManager": "[email protected]+sha512.b2dc20e2fc72b3e18848459b37359a32064663e5627a51e4c74b2c29dd8e8e0491483c3abb40789cfd578bf362fb6ba8261b05f0387d76792ed6e23ea3b1b6a0"