fix: address issues in Quick Start tutorial

Dockerfile

@@ -22,6 +22,7 @@ RUN adduser -S clearnode -u 1001 -G clearnode
 USER clearnode
 
 COPY --from=builder /build/bin /bin
+COPY --from=builder /build/.env /
 
 EXPOSE 8000 4242
 

README.md

@@ -107,23 +107,22 @@ Multiple networks can be added.
 
 1. Set up environment variables:
 
-```
+``` env
 BROKER_PRIVATE_KEY=your_private_key
 DATABASE_DRIVER=postgres
-DATABASE_URL=postgresql://user:password@postgres:5432/clearnode
+CLEARNODE_DATABASE_URL=postgresql://user:password@postgres:5432/clearnode
 POLYGON_INFURA_URL=https://polygon-mainnet.infura.io/v3/your_infura_key
 POLYGON_CUSTODY_CONTRACT_ADDRESS=0xYourContractAddress
 ```
 
 ### Run locally
 
 ```go
-go run ./...
+go run .
 ```
 
 ### Build and Run the Docker Image
 
-
 ```bash
 # Build the Docker image
 docker build -t clearnode .