Clarify where documentation lives.
@@ -49,8 +49,10 @@ $ ./check.sh tests shell/tests
## Documentation
-To build the [documentation](http://probcomp.csail.mit.edu/dev/bayesdb/doc/)
-(requires sphinx):
+To build the documentation, which is also available
+[online](http://probcomp.csail.mit.edu/dev/bayesdb/doc/),
+install [sphinx](http://www.sphinx-doc.org/en/master/)
+and then run the following command:
```
$ make doc
