docs(upgrading): add generate-clients doc dependencies (#2224)

PaulThompson · AllanZhengYP · web-flow · commit 56dae4e317aa · 2021-04-16T17:16:40.000-07:00
* docs(generate-clients): mention smithy-typescript dependency

Co-authored-by: AllanZhengYP &lt;zheallan@amazon.com&gt;
diff --git a/scripts/generate-clients/README.md b/scripts/generate-clients/README.md
@@ -2,7 +2,8 @@
 
 ## Prerequisite
 
-This script requires Node.js >= 12
+* Node.js version >= 12.
+* [Build and publish Smithy-TypeScript locally](https://github.com/awslabs/smithy-typescript#steps-to-build).
 
 ## Options:
 
