Merge pull request #39 from landermkerbey/patch-1

Added missing comma in "What is AWS"

Author: spaethp

doc_source/welcome.md

@@ -36,4 +36,4 @@ The following topics provide additional information about AWS Lambda:
 + [AWS Lambda Function Versioning and Aliases](versioning-aliases.md)
 + [Using Amazon CloudWatch](monitoring-functions.md)
 + [Best Practices for Working with AWS Lambda Functions](best-practices.md)
-+ [AWS Lambda Limits](limits.md)
++ [AWS Lambda Limits](limits.md)