Making header shorter per feedback

Author: deborahc

articles/cosmos-db/use-notebook-features-and-commands.md

@@ -139,7 +139,7 @@ custom_connection_policy.PreferredLocations = [region_1, region_2] # Set the ord
 # Create a new instance of CosmosClient, getting the endpoint and key from the environment variables
 custom_client = cosmos.CosmosClient(os.environ["COSMOS_ENDPOINT"], {'masterKey': os.environ["COSMOS_KEY"]}, connection_policy=custom_connection_policy)
 ```
-## Access the account endpoint and primary key environment variables
+## Access the account endpoint and primary key env variables
 ```python
 import os