docs: add BMad Ecosystem cross-links to sidebar (#58)

Author: bmadcode

website/astro.config.mjs

@@ -104,6 +104,16 @@ export default defineConfig({
           collapsed: true,
           autogenerate: { directory: 'reference' },
         },
+        {
+          label: 'BMad Ecosystem',
+          collapsed: false,
+          items: [
+            { label: 'BMad Method', link: 'https://docs.bmad-method.org/', attrs: { target: '_blank' } },
+            { label: 'Creative Intelligence Suite', link: 'https://cis-docs.bmad-method.org/', attrs: { target: '_blank' } },
+            { label: 'Game Dev Studio', link: 'https://game-dev-studio-docs.bmad-method.org/', attrs: { target: '_blank' } },
+            { label: 'Test Architect (TEA)', link: 'https://bmad-code-org.github.io/bmad-method-test-architecture-enterprise/', attrs: { target: '_blank' } },
+          ],
+        },
       ],
 
       // Credits in footer