Update contributing.md

Author: hsubox76

docs/contributing.md

@@ -39,10 +39,8 @@ Steps to build locally:
 1. Run `yarn format` to fix formatting and add license headers as needed.
 1. Run `yarn changeset` to generate the changeset summary.
 
-This repo has a monorepo structure to allow for easily adding additional packages. The `@google/generative-ai` package code is in `packages/main`.
-
 ### Code Reviews
 
 All submissions, including submissions by project members, require review. We
 use [GitHub pull requests](https://docs.github.com/articles/about-pull-requests)
-for this purpose.
+for this purpose.