Update CODEOWNERS (#8342)

* Update CODEOWNERS

Added owners for official and research model folders
Removed owners of removed folders

* Update README.md

Added new introduction messages for the Model Garden

CODEOWNERS

-* @tensorflow/tf-garden-team
+* @tensorflow/tf-garden-team @tensorflow/tf-model-garden-team
 /official/ @rachellj218 @saberkun
 /official/bert @saberkun @hongjunChoi @rachellj218
+/research/adv_imagenet_models/ @alexeykurakin
 /research/adversarial_crypto/ @dave-andersen
-/research/adversarial_logit_pairing/ @AlexeyKurakin
+/research/adversarial_logit_pairing/ @alexeykurakin
 /research/adversarial_text/ @rsepassi @a-dai
-/research/adv_imagenet_models/ @AlexeyKurakin
+/research/astronet/ @cshallue
 /research/attention_ocr/ @alexgorban
 /research/audioset/ @plakal @dpwe
 /research/autoaugment/* @barretzoph
@@ -14,10 +15,13 @@
 /research/compression/ @nmjohn
 /research/cvt_text/ @clarkkev @lmthang
 /research/deep_contextual_bandits/ @rikel
+/research/deep_speech/ @yhliang2018
 /research/deeplab/ @aquariusjay @yknzhu @gpapan
 /research/delf/ @andrefaraujo
 /research/domain_adaptation/ @bousmalis @dmrd
 /research/efficient-hrl/ @ofirnachum
+/research/feelvos/ @pvoigtlaender @yuningchai @aquariusjay
+/research/fivo/ @dieterichlawson
 /research/global_objectives/ @mackeya-google
 /research/im2txt/ @cshallue
 /research/inception/ @shlens @vincentvanhoucke
@@ -39,9 +43,10 @@
 /research/object_detection/ @jch1 @tombstone @derekjchow @jesu9 @dreamdragon @pkulzc
 /research/pcl_rl/ @ofirnachum
 /research/ptn/ @xcyan @arkanath @hellojas @honglaklee
+/research/qa_kg/ @yuyuz
 /research/real_nvp/ @laurent-dinh
 /research/rebar/ @gjtucker
-/research/resnet/ @panyx0718
+/research/sentiment_analysis/ @sculd
 /research/seq2species/ @apbusia @depristo
 /research/skip_thoughts/ @cshallue
 /research/slim/ @sguada @nathansilberman
@@ -50,15 +55,7 @@
 /research/struct2depth/ @aneliaangelova
 /research/swivel/ @waterson
 /research/tcn/ @coreylynch @sermanet
-/research/tensorrt/ @karmel
 /research/textsum/ @panyx0718 @peterjliu
 /research/transformer/ @daviddao
 /research/vid2depth/ @rezama
 /research/video_prediction/ @cbfinn
-/research/fivo/ @dieterichlawson
-/samples/ @MarkDaoust @lamberta
-/samples/languages/java/ @asimshankar
-/tutorials/embedding/ @zffchen78 @a-dai
-/tutorials/image/ @sherrym @shlens
-/tutorials/image/cifar10_estimator/ @protoget
-/tutorials/rnn/ @lukaszkaiser @ebrevdo

README.md

 ![Logo](https://storage.googleapis.com/model_garden_artifacts/TF_Model_Garden.png)
 
-# TensorFlow Models
+# Welcome to the Model Garden for TensorFlow
 
-This repository contains a number of different models implemented in [TensorFlow](https://www.tensorflow.org):
+The TensorFlow Model Garden is a repository with a number of different implmentations of state-of-the-art (SOTA) models and modeling solutions for TensorFlow users. We aim to demonstrate the best practices for modeling so that TensorFlow users can take full advantage of TensorFlow for their research and product development.
 
-The [official models](official) are a collection of example models that use TensorFlow 2's high-level APIs. They are intended to be well-maintained, tested, and kept up to date with the latest stable TensorFlow API. They should also be reasonably optimized for fast performance while still being easy to read. We especially recommend newer TensorFlow users to start here.
+## Structure
 
-The [research models](https://github.com/tensorflow/models/tree/master/research) are a large collection of models implemented in TensorFlow by researchers. They are not officially supported or available in release branches; it is up to the individual researchers to maintain the models and/or provide support on issues and pull requests.
+| Folder | Description |
+|-----------|-------------|
+| [official](official) | • **A collection of example implementations for SOTA models using the latest TensorFlow 2's high-level APIs**<br />• Officially maintained, supported, and kept up to date with the latest TensorFlow 2 APIs<br />• Reasonably optimized for fast performance while still being easy to read |
+| [research](research) | • A collection of research model implementations in TensorFlow 1 or 2 by researchers<br />• Up to the individual researchers to maintain the model implementations and/or provide support on issues and pull requests |
 
 ## Contribution guidelines
 
-If you want to contribute to models, be sure to review the [contribution guidelines](CONTRIBUTING.md).
+If you want to contribute to models, please review the [contribution guidelines](CONTRIBUTING.md).
 
 ## License