Split `run_config` into `run_config download` and `run_config generate`.

README.md

Index: README.md
diff --git a/README.md b/README.md
index a33047ac5b84a0e91a7f27941dad4c0aa2736fc7..79fe79bf8d4329a9fe8760aa2f43cf07eadbcbc4 100644
--- a/README.md
+++ b/README.md
@@ -9,13 +9,22 @@ Repository for building the [googleapis] and [googleapis_beta] packages.
 
 - Download & generate APIs using the `config.yaml` configuration:
 
-    $ dart bin/generate.dart run_config
+    $ dart bin/generate.dart run_config download
+
+- Possible reset some of the discovery documents downloaded (e.g. drive,
+  prediction)
+
+- Generate APIs
+
+    $ dart bin/generate.dart run_config generate
 
 - Diff with previous APIs and determine whether to do minor or major version
   update. Update CHANGELOG.md files in resources/.
 
 - Update `config.yaml` with new version and generate again.
 
+    $ dart bin/generate.dart run_config generate
+
 - Run tests:
 
     $ pub global activate test_runner