Add example GQL queries

stack_orchestrator/data/stacks/merkl-sushiswap-v3/README.md

@@ -72,6 +72,26 @@ laconic-so deployment --dir merkl-sushiswap-v3-deployment start
   docker logs -f <CONTAINER_ID>
   ```
 
+* Open the GQL playground at http://localhost:3007/graphql
+
+  ```graphql
+  # Example query
+  {
+    _meta {
+      block {
+        number
+        timestamp
+      }
+      hasIndexingErrors
+    }
+
+    factories {
+      id
+      poolCount
+    }
+  }
+  ```
+
 ## Clean up
 
 Stop all the merkl-sushiswap-v3 services running in background:

stack_orchestrator/data/stacks/sushiswap-v3/README.md

@@ -72,6 +72,26 @@ laconic-so deployment --dir sushiswap-v3-deployment start
   docker logs -f <CONTAINER_ID>
   ```
 
+* Open the GQL playground at http://localhost:3008/graphql
+
+  ```graphql
+  # Example query
+  {
+    _meta {
+      block {
+        number
+        timestamp
+      }
+      hasIndexingErrors
+    }
+
+    factories {
+      id
+      poolCount
+    }
+  }
+  ```
+
 ## Clean up
 
 Stop all the sushiswap-v3 services running in background: