Add instructions on how to generate doc (pytorch#1995)

Summary:

Instructions copied from torchtnt

Differential Revision: D57286941

docs/README.md

@@ -0,0 +1,23 @@
+Docs
+==========
+
+
+## Building the docs
+
+To build and preview the docs run the following commands:
+
+```bash
+cd docs
+pip3 install -r requirements.txt
+make html
+python3 -m http.server 8082 --bind ::
+```
+
+Now you should be able to view the docs in your browser at the link provided in your terminal.
+
+To reload the preview after making changes, rerun:
+
+```bash
+make html
+python3 -m http.server 8082 --bind ::
+```

docs/source/conf.py

@@ -34,9 +34,15 @@
 copyright = "2022, Meta"
 author = "Meta"
 
+try:
+    # pyre-ignore
+    version = torchrec.__version__
+except Exception:
+    # when run internally, we don't have a version yet
+    version = "0.0.0"
 # The full version, including alpha/beta/rc tags
 # First 3 as format is 0.x.x.*
-release = ".".join(torchrec.__version__.split(".")[:3])
+release = ".".join(version.split(".")[:3])
 
 # -- General configuration ---------------------------------------------------