chore: Polish the language to recommend Lambda Extension over forwarder (#911)

Polish the language to recommend Lambda Extension over forwarder

Polishes the language to make it clear that Datadog Lambda Extension is perferred over Forwarder to monitor Lambda functions.

Open to changes if you have a better way to clarify this.

Fix spaces

Co-authored-by: yiming.luo <yiming.luo@datadoghq.com>

Author: lym953

aws/logs_monitoring/README.md

@@ -15,7 +15,7 @@ The Datadog Forwarder is an AWS Lambda function that ships logs from AWS to Data
 -   Forward CloudWatch and S3 logs.
 -   Forward logs from SNS, and Kinesis events to Datadog.
 -   Kinesis data stream events support CloudWatch logs only.
--   Forward metrics, traces, and logs from AWS Lambda functions to Datadog. Datadog recommends to use [Datadog Lambda Extension][1] to monitor Lambda functions.
+-   Forward metrics, traces, and logs from AWS Lambda functions to Datadog. However, instead of using a forwarder, Datadog recommends to use [Datadog Lambda Extension][1] to monitor Lambda functions.
 
 For Serverless customers using the Forwarder to forward metrics, traces, and logs from AWS Lambda logs to Datadog, you should [migrate to the Datadog Lambda Extension][3] to collect telemetry directly from the Lambda execution environments. The Forwarder is still available for use in Serverless Monitoring, but will not be updated to support the latest features.