chore: add smithy to codeowners (#4333)

.github/CODEOWNERS

@@ -1 +1,41 @@
 * @aws/aws-sdk-js-team
+
+# These packages are used by Smithy generated code
+packages/config-resolver/* @aws/smithy
+packages/eventstream-serde-browser/* @aws/smithy
+packages/eventstream-serde-config-resolver/* @aws/smithy
+packages/eventstream-serde-node/* @aws/smithy
+packages/fetch-http-handler/* @aws/smithy
+packages/hash-blob-browser/* @aws/smithy
+packages/hash-node/* @aws/smithy
+packages/hash-stream-node/* @aws/smithy
+packages/invalid-dependency/* @aws/smithy
+packages/md5-js/* @aws/smithy
+packages/middleware-apply-body-checksum/* @aws/smithy
+packages/middleware-content-length/* @aws/smithy
+packages/middleware-endpoint/* @aws/smithy
+packages/middleware-retry/* @aws/smithy
+packages/middleware-serde/* @aws/smithy
+packages/middleware-stack/* @aws/smithy
+packages/node-http-handler/* @aws/smithy
+packages/protocol-http/* @aws/smithy
+packages/querystring-builder/* @aws/smithy
+packages/service-client-documentation-generator/* @aws/smithy
+packages/smithy-client/* @aws/smithy
+packages/types/* @aws/smithy
+packages/url-parser/* @aws/smithy
+packages/util-base64/* @aws/smithy
+packages/util-base64-browser/* @aws/smithy
+packages/util-base64-node/* @aws/smithy
+packages/util-body-length-browser/* @aws/smithy
+packages/util-body-length-node/* @aws/smithy
+packages/util-defaults-mode-browser/* @aws/smithy
+packages/util-defaults-mode-node/* @aws/smithy
+packages/util-endpoints/* @aws/smithy
+packages/util-middleware/* @aws/smithy
+packages/util-retry/* @aws/smithy
+packages/util-stream-browser/* @aws/smithy
+packages/util-stream-node/* @aws/smithy
+packages/util-utf8-browser/* @aws/smithy
+packages/util-utf8-node/* @aws/smithy
+packages/util-waiter/* @aws/smithy