Add Test Systems section to sidebar (Nordic + 5-bus)

Author: apetros

astro.config.mjs

@@ -102,6 +102,13 @@ export default defineConfig({
 						{ label: 'URAMSES', slug: 'developer/uramses' },
 					],
 				},
+				{
+					label: 'Test Systems',
+					items: [
+						{ label: 'Nordic Test System', slug: 'test-systems/nordic' },
+						{ label: '5-Bus Test System', slug: 'test-systems/5bus' },
+					],
+				},
 				{
 					label: 'Resources',
 					items: [