docs: rewrite landing page (#60)

Author: kylehounslow

AGENTS.md

@@ -826,6 +826,10 @@ helm uninstall observability-stack-test
 - Provide both quick start and detailed explanations
 - Include troubleshooting sections
 
+### Icons
+
+Use OpenSearch UI (OUI) icons for documentation components. Browse the full set at https://oui.opensearch.org/1.23/#/display/icons. SVG sources are at https://github.com/opensearch-project/oui/tree/main/src/components/icon/assets. Prefer 32x32 icons over 16x16 for consistent sizing.
+
 ### Examples
 
 - Include complete, runnable code

CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md

docs/public/opensearch-logo-lightmode.svg

@@ -16,53 +16,75 @@ export default defineConfig({
 			logo: {
 				src: './src/assets/opensearch-logo-darkmode.svg',
 			},
+			editLink: {
+				baseUrl: 'https://github.com/opensearch-project/observability-stack/edit/main/docs/starlight-docs/',
+			},
+			customCss: [
+				'./src/styles/custom.css',
+			],
 			social: [{ icon: 'github', label: 'GitHub', href: 'https://github.com/opensearch-project/observability-stack' }],
 			components: {
 				Header: './src/components/CustomHeader.astro',
+				PageSidebar: './src/components/PageSidebar.astro',
 			},
 			sidebar: [
+				{
+					label: 'Overview',
+					link: '/',
+				},
 				{
 					label: 'Get Started',
+					collapsed: true,
 					autogenerate: { directory: 'get-started' },
 				},
 				{
 					label: 'Send Data',
+					collapsed: true,
 					autogenerate: { directory: 'send-data' },
 				},
 				{
 					label: 'Investigate',
+					collapsed: true,
 					autogenerate: { directory: 'investigate' },
 				},
 				{
 					label: 'Application Monitoring',
+					collapsed: true,
 					autogenerate: { directory: 'apm' },
 				},
 				{
 					label: 'Dashboards & Visualize',
+					collapsed: true,
 					autogenerate: { directory: 'dashboards' },
 				},
 				{
 					label: 'AI Observability',
+					collapsed: true,
 					autogenerate: { directory: 'ai-observability' },
 				},
 				{
 					label: 'MCP Server',
+					collapsed: true,
 					autogenerate: { directory: 'mcp' },
 				},
 				{
 					label: 'Alerting',
+					collapsed: true,
 					autogenerate: { directory: 'alerting' },
 				},
 				{
 					label: 'Anomaly Detection',
+					collapsed: true,
 					autogenerate: { directory: 'anomaly-detection' },
 				},
 				{
 					label: 'Forecasting',
+					collapsed: true,
 					autogenerate: { directory: 'forecasting' },
 				},
 				{
 					label: 'SDKs & API',
+					collapsed: true,
 					autogenerate: { directory: 'sdks' },
 				},
 			],