feat: add content to sidebar navigation

Author: aaronbassett

apps/developer-hub/content/docs/pyth-core/meta.json

@@ -3,5 +3,19 @@
   "title": "Pyth Core",
   "description": "Real-time data from financial institutions",
   "icon": "ChartLine",
-  "pages": ["index", "---Guides---", "how-to-guides"]
+  "pages": ["index", "getting-started", "---Tutorials---", "create-your-first-pyth-app",  "---Guides---", "use-real-time-data", "fetch-price-updates", "schedule-price-updates",
+  "migrate-an-app-to-pyth",
+  "use-pyth-for-morpho",
+  "publish-data",
+  "troubleshoot", "---Reference Material---", "api-reference",
+  "price-feeds",
+  "current-fees",
+  "sponsored-feeds",
+  "market-hours",
+  "best-practices",
+  "error-codes",
+  "api-instances-and-providers",
+  "contract-addresses",
+  "pythnet-reference", "---Understand Pyth---", "pull-updates",
+  "how-pyth-works"]
 }