docs(aws-lambda): add name format description for aws lambda plugin (#…

…12782)

This PR adds a detailed description for the function_name format of the aws-lambda plugin.

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Co-authored-by: Aapo Talvensaari <aapo.talvensaari@gmail.com>

kong/plugins/aws-lambda/schema.lua

@@ -42,7 +42,7 @@ return {
         { function_name = {
           type = "string",
           required = false,
-          description = "The AWS Lambda function name to invoke."
+          description = "The AWS Lambda function to invoke. Both function name and function ARN (including partial) are supported."
         } },
         { qualifier = {
           type = "string",