Comma added to install_requires

A Comma needed to be added to the end of the install_requires list. This allows for easy copy/pasting

Author: johnculkin

doc_source/work-with-cdk-v2.md

@@ -135,7 +135,7 @@ install_requires=[
      "aws-cdk-lib>=2.0.0rc1",
      "constructs>=10.0.0",
      # ...
-]
+],
 ```
 
 Install the new dependencies with `pip install -r requirements.txt`\.
@@ -239,4 +239,4 @@ Before deploying your app, use `cdk diff` to check for unexpected changes to its
 If your upgraded app ends up undeployable after the two\-stage upgrade, please [report the issue](https://github.com/aws/aws-cdk/issues/new/choose)\.
 
 **Typescript `'from' expected` or `';' expected` error in imports**  
-Upgrade to TypeScript 3\.8 or later\.
+Upgrade to TypeScript 3\.8 or later\.