docs: fix dashboard backend source paths

Author: haosenwang1018

README.md

@@ -179,7 +179,7 @@ git clone https://github.com/CaviraOSS/OpenMemory.git
 cd OpenMemory
 cp .env.example .env
 
-cd backend
+cd packages/openmemory-js
 npm install
 npm run dev   # default :8080
 ```

dashboard/CHAT_SETUP.md

@@ -17,7 +17,7 @@ The chat interface is now connected to the OpenMemory backend and can query memo
 First, make sure the OpenMemory backend is running:
 
 ```bash
-cd backend
+cd packages/openmemory-js
 npm install
 npm run dev
 ```