docs: add og image

Author: HiDeoo

docs/astro.config.ts

@@ -2,13 +2,30 @@ import starlight from '@astrojs/starlight'
 import { defineConfig } from 'astro/config'
 import starlightChangelogs, { makeChangelogsSidebarLinks } from 'starlight-changelogs'
 
+const site =
+  (process.env['CONTEXT'] === 'production' ? process.env['URL'] : process.env['DEPLOY_PRIME_URL']) ??
+  'https://starlight-changelogs.netlify.app/'
+
 export default defineConfig({
   integrations: [
     starlight({
       description: 'Starlight plugin to display changelogs alongside your project documentation.',
       editLink: {
         baseUrl: 'https://github.com/HiDeoo/starlight-changelogs/edit/main/docs/',
       },
+      head: [
+        {
+          tag: 'meta',
+          attrs: { property: 'og:image', content: new URL('og.jpg', site).href },
+        },
+        {
+          tag: 'meta',
+          attrs: {
+            property: 'og:image:alt',
+            content: 'Starlight plugin to display changelogs alongside your project documentation.',
+          },
+        },
+      ],
       plugins: [starlightChangelogs()],
       sidebar: [
         {
@@ -69,6 +86,6 @@ export default defineConfig({
       title: 'Starlight Changelogs',
     }),
   ],
-  site: 'https://starlight-changelogs.netlify.app/',
+  site,
   trailingSlash: 'always',
 })