Add decord instructions to README (#82)

* Add decord instructions

* Add references to PRs

Author: mmuckley

README.md

@@ -293,6 +293,8 @@ conda activate vjepa2-312
 pip install .  # or `pip install -e .` for development mode
 ```
 
+**Note to macOS users:** V-JEPA 2 relies on [`decord`](https://github.com/dmlc/decord), which does not support macOS (and, unfortunately, is also no longer under development). In order to run the V-JEPA 2 code on macOS, you will need a different `decord` implementation. We do not make specific recommendations, although some users have reported the use of [`eva-decord`](https://github.com/georgia-tech-db/eva-decord) (see [PR 1](https://github.com/facebookresearch/vjepa2/pull/1)) or [`decord2`](https://github.com/johnnynunez/decord2) (see [PR 31](https://github.com/facebookresearch/vjepa2/pull/31)).  We leave the selection of the `decord` package up to the user's discretion.
+
 ### Usage Demo
 
 See [vjepa2_demo.ipynb](notebooks/vjepa2_demo.ipynb) [(Colab Link)](https://colab.research.google.com/github/facebookresearch/vjepa2/blob/main/notebooks/vjepa2_demo.ipynb) or [vjepa2_demo.py](notebooks/vjepa2_demo.py) for an example of how to load both the HuggingFace and PyTorch V-JEPA 2 models and run inference on a sample video to get a sample classification result.