README edit to change Apple Silicon install instructions (to fix a break introduced by pytorch 2)
git clone and cd'ing into NeMo became obsolete when installing from pypi. Imo those commands can be removed?
```shell
git clone https://github.com/NVIDIA/NeMo
cd NeMo
```
In my case, I only get v1.21 installed from pypi. With `pip install 'nemo-toolkit[asr]==1.22.0'` I again run into an triton dependency issue:
`ERROR: Could not find a version that satisfies the requirement triton (from nemo-toolkit) (from versions: none)` According to [this comment](https://github.com/openai/triton/issues/1057#issuecomment-1500691831), macOS is not supported by triton at all.
What eventually _did_ work for me was removing `triton` from the requirements altogether and install from the local checkout.
`$ pip install '.[asr]'`
# What does this PR do ?

This PR aims to correct a small error in the Apple Silcon installation instructions in README, where a triton dependency is problematic due to pytorch 2. The use of `/reinstall.sh` doesn't work, so using `pip install` instead. Also added a note about MacBook, to clarify that only asr toolkit is supported.

# Additional Information
* Related to #8116

