ref wundergraph#67: fix(docs): correct onboarding guide URLs for playground and employees subgraph

Author: Sudheesh Rao Moghe

docs/getting-started/cosmo-cloud-onboarding.mdx

@@ -116,7 +116,7 @@ For this demo, you'll use pre-deployed demo subgraphs on a serverless platform.
     ```bash
     wgc subgraph create employees \
         --namespace development \
-        --routing-url https://employee-api.fly.dev/graphql
+        --routing-url https://employees-api.fly.dev/graphql
     ```
 
     1. Download the schema and publish it:
@@ -235,7 +235,7 @@ docker run \
 
 ### Open the Playground
 
-Open [http://localhost:3002](http://localhost:3002/graphql) and run your first GraphQL operation with WunderGraph Cosmo\!  The same playground is also available on Cosmo Cloud.
+Open [http://localhost:3002](http://localhost:3002) and run your first GraphQL operation with WunderGraph Cosmo\!  The same playground is also available on Cosmo Cloud.
 
 ### Example Query that involves all subgraphs