[docs] add ray tune tutorial link to sidebar and readme (Lightning-AI#2648)

Co-authored-by: Kai Fricke <kai@anyscale.com>

Author: krfricke

Diff for: README.md

@@ -361,6 +361,7 @@ Check out this awesome list of research papers and implementations done with Lig
 - [Contextual Emotion Detection (DoubleDistilBert)](https://github.com/PyTorchLightning/emotion_transformer)
 - [Generative Adversarial Network](https://colab.research.google.com/drive/1F_RNcHzTfFuQf-LeKvSlud6x7jXYkG31#scrollTo=TyYOdg8g77P0)
 - [Hyperparameter optimization with Optuna](https://github.com/optuna/optuna/blob/master/examples/pytorch_lightning_simple.py)
+- [Hyperparameter optimization with Ray Tune](https://docs.ray.io/en/master/tune/tutorials/tune-pytorch-lightning.html)
 - [Image Inpainting using Partial Convolutions](https://github.com/ryanwongsa/Image-Inpainting)
 - [MNIST on TPU](https://colab.research.google.com/drive/1-_LKx4HwAxl5M6xPJmqAAu444LTDQoa3#scrollTo=BHBz1_AnamN_)
 - [NER (transformers, TPU, huggingface)](https://colab.research.google.com/drive/1dBN-wwYUngLYVt985wGs_OKPlK_ANB9D)

Diff for: docs/source/index.rst

@@ -43,6 +43,7 @@ PyTorch Lightning Documentation
    Cotatron: Transcription-Guided Speech Encoder <https://github.com/mindslab-ai/cotatron>
    FasterRCNN object detection + Hydra <https://github.com/PyTorchLightning/wheat>
    Hyperparameter optimization with Optuna <https://github.com/optuna/optuna/blob/master/examples/pytorch_lightning_simple.py>
+   Hyperparameter optimization with Ray Tune <https://docs.ray.io/en/master/tune/tutorials/tune-pytorch-lightning.html>
    Image Inpainting using Partial Convolutions <https://github.com/ryanwongsa/Image-Inpainting>
    MNIST on TPU <https://colab.research.google.com/drive/1-_LKx4HwAxl5M6xPJmqAAu444LTDQoa3#scrollTo=BHBz1_AnamN_>
    NER (transformers, TPU) <https://colab.research.google.com/drive/1dBN-wwYUngLYVt985wGs_OKPlK_ANB9D>