Add pyre external (pytorch#1000)

Summary:
Pull Request resolved: pytorch#1000

ATT following https://www.internalfb.com/intern/staticdocs/pyre/docs/fb/open-source-setup/

Reviewed By: colin2328

Differential Revision: D42891790

fbshipit-source-id: 447346889f54eb704f727389f511d5371a820c34

.pyre_configuration

@@ -0,0 +1,11 @@
+{
+  "exclude": [
+    ".*/pyre-check/stubs/.*"
+  ],
+  "site_package_search_strategy": "all",
+  "source_directories": [
+    "torchrec"
+  ],
+  "strict": true,
+  "version": "0.0.101674562297"
+}

README.MD

@@ -93,5 +93,25 @@ We are currently iterating on the setup experience. For now, we provide manual i
 
 5. If you want to run a more complex example, please take a look at the torchrec [DLRM example](https://github.com/facebookresearch/dlrm/blob/main/torchrec_dlrm/dlrm_main.py).
 
+## Contributing
+
+### Pyre and linting
+
+Before landing, please make sure that pyre and linting look okay. To run our linters, you will need to
+```
+pip install pre-commit
+```
+
+, and run it.
+
+For Pyre, you will need to
+```
+cat .pyre_configuration
+pip install pyre-check-nightly==<VERSION FROM CONFIG>
+pyre check
+```
+
+We will also check for these issues in our GitHub actions.
+
 ## License
 TorchRec is BSD licensed, as found in the [LICENSE](LICENSE) file.