Update README.md

Co-authored-by: Dominic Chapman <dominicchapman@users.noreply.github.com>

README.md

@@ -5,7 +5,7 @@ Axiom CloudWatch Forwarder is a set of easy-to-use AWS CloudFormation stacks des
 Axiom CloudWatch Forwarder includes templates for the following CloudFormation stacks:
 
 - Axiom Forwarder creates a Lambda function that ingests logs from CloudWatch and sends them to Axiom.
-- Subscriber runs once to create subscription filters on the ingest Lambda for all existing CloudWatch log groups.
+- _Subscriber_ runs once to create subscription filters on the _Forwarder_ Lambda for CloudWatch log groups specified by a combination of names, prefix and regular expression.
 - LogGroups Listener creates a Lambda function that listens for new log groups and creates subscription filters for them. This way, you don't have to create subscription filters manually for new log groups.
 
 ## Guide