Add top-level links in README.md (#121)

Summary:
Add a bunch of relevant links at the very-top of the README. I think we'll need to merge this before we can check whether the links are properly working.

Also made some minor README-related changes.

Pull Request resolved: #121

Reviewed By: ahmadsharif1

Differential Revision: D60375936

Pulled By: NicolasHug

fbshipit-source-id: 72bd52e97b13eaae7f98b179094929329a494398

Author: NicolasHug

README.md

@@ -1,20 +1,21 @@
-<!-- TODO_BEFORE_RELEASE Add obvious link to docs and potentially a tag as
-well-->
+[**Installation**](#installing-torchcodec) | [**Simple Example**](#using-torchcodec) | [**Detailed Example**](https://pytorch.org/torchcodec/stable/generated_examples/) | [**Documentation**](https://pytorch.org/torchcodec) | [**Contributing**](CONTRIBUTING.md) | [**License**](#license)
 
 # TorchCodec
 
 TorchCodec is a Python package with a goal to provide useful and fast APIs to
 decode video frames to PyTorch Tensors.
 
-⚠️ TorchCodec is still in early development stage and we are actively seeking
-feedback. If you have any suggestions or issues, please let us know by [opening
-an issue](https://github.com/pytorch/torchcodec/issues/new/choose)!
+> [!NOTE]
+> ⚠️ TorchCodec is still in early development stage and some APIs may be updated
+> in future versions without a deprecation cycle, depending on user feedback.
+> If you have any suggestions or issues, please let us know by
+> [opening an issue](https://github.com/pytorch/torchcodec/issues/new/choose)!
 
 ## Using TorchCodec
 
 Here's a condensed summary of what you can do with TorchCodec. For a more
 detailed example, [check out our
-documentation](https://pytorch.org/torchcodec/main/generated_examples/)!
+documentation](https://pytorch.org/torchcodec/stable/generated_examples/)!
 
 ```python
 from torchcodec.decoders import SimpleVideoDecoder
@@ -92,10 +93,9 @@ capabilities are determined by your underlying FFmpeg installation. There are
 different options to install FFmpeg e.g.:
 
 ```bash
-
-    conda install ffmpeg
-    # or
-    conda install ffmpeg -c conda-forge
+conda install ffmpeg
+# or
+conda install ffmpeg -c conda-forge
 ```
 
 Your Linux distribution probably comes with FFmpeg pre-installed as well.