Add note about Apple silicon to readme
@@ -39,7 +39,15 @@ Install the package:
$ pip install mhcflurry
```
-Then download our datasets and trained models:
+If you don't already have it, you will also need to install tensorflow version 2.2.0 or later. On most platforms you can do this with:
+
+```
+$ pip install tensorflow
+```
+
+If you are on Apple silicon (M1 processor), then you'll need to run `pip install tensorflow-macos` instead. See these [instructions](https://caffeinedev.medium.com/how-to-install-tensorflow-on-m1-mac-8e9b91d93706) for more info.
+
+Next download our datasets and trained models:
```
$ mhcflurry-downloads fetch
