Update readme to add attribution step

Signed-off-by: Judy Ng <njud@amazon.com>

DEVELOPMENT.md

@@ -29,11 +29,14 @@ When working on the project, you may need to add/change a dependency.
 ### Product Dependencies
 To add a product dependency, you should add the dependency with a specified version to the `requirements.in` file, 
 and generate `requirements.txt` using [pip-tools](https://github.com/jazzband/pip-tools),
-which is part of dev dependencies (`requirements-dev.txt`)
+which is part of dev dependencies (`requirements-dev.txt`). Then update the attribution document in
+`frontend/resources/attributions/npm-python-attributions.txt` accordingly 
+in the "Python third party dependencies" section.
 
 When changing a dependency in the frontend project you should add/Change it in `frontend/package.json`,
 re-generate `frontend/package-lock.json` with `npm install` 
-and update the attribution document in `frontend/resources/attributions/npm-python-attributions.txt` accordingly.
+and update the attribution document in `frontend/resources/attributions/npm-python-attributions.txt` accordingly
+in the "Javascript third party dependencies" section.
 
 ### Dev Dependencies
 To add/change a development dependencies, you can directly change `requirements-dev.txt`.