Fix typo in readme server url (frequenz-floss#96)

Addresses comments from PR frequenz-floss#95

Author: flora-hofmann-frequenz

README.md

@@ -44,9 +44,9 @@ from frequenz.client.common.metric import Metric
 from frequenz.client.reporting import ReportingApiClient
 
 # Change server address if needed
-SERVICE_URL = "grpc://reporting.api.frequenz.com:443?ssl=true"
+SERVER_URL = "grpc://reporting.api.frequenz.com:443?ssl=true"
 API_KEY = open('api_key.txt').read().strip()
-client = ReportingApiClient(service_url=SERVICE_URL, key=API_KEY)
+client = ReportingApiClient(server_url=SERVER_URL, key=API_KEY)
 ```
 
 Besides the microgrid_id, component_ids, and metrics, start, and end time,

RELEASE_NOTES.md

@@ -6,7 +6,7 @@
 
 ## Upgrading
 
-* Update readme to make use of newest release version 0.8.0
+* Update and fix readme to make use of newest release version 0.8.0
 
 ## New Features