Updated README (lambda-client#427)

Changed the title "Thanks to" to "Thanks to...". This makes more sense as there is a pause from reading the title to seeing the contributors list, and the other stuff, so it makes sense to put three dots to indicate the following will continue what is being communicated.

Author: CozyMeli-gitv2

README.md

@@ -124,7 +124,7 @@ Test if the environment is set up correctly by building the client and running i
 ### Stargazers
 [![Stargazers](https://starchart.cc/lambda-client/lambda.svg)](https://starchart.cc/lambda-client/lambda)
 
-## Thanks to
+## Thanks to...
 
 Our [contributors](https://github.com/lambda-client/lambda/graphs/contributors)