docs(mysql,s3): v2.4.1 MySQL pool docs in 2.4.x, and S3 changes JSON Lines formats (#2495) * docs(mysql): document the v2.4.1 pool validation, connection lifetime, and connection log in 2.4.x * docs(mysql,s3): qualify the changes-mode idle close and list the JSON Lines formats S3 changes accepts * docs(s3): an in-place overwrite does not trigger s3_on_object_removed: rebuild * docs(s3): add the SQS queue policy S3 needs to deliver notifications

docs(mysql,s3): v2.4.1 MySQL pool docs in 2.4.x, and S3 changes JSON Lines formats (#2495) * docs(mysql): document the v2.4.1 pool validation, connection lifetime, and connection log in 2.4.x * docs(mysql,s3): qualify the changes-mode idle close and list the JSON Lines formats S3 changes accepts * docs(s3): an in-place overwrite does not trigger s3_on_object_removed: rebuild * docs(s3): add the SQS queue policy S3 needs to deliver notifications