Updated Contributing.md

CONTRIBUTING.md

@@ -365,6 +365,7 @@ From time to time, our team will add tutorials that will help contributors find
 * [Adding Support for a New OAuth2 Provider](./docs/tutorials/add-oauth2-provider.md)
 * [Appwrite Environment Variables](./docs/tutorials/environment-variables.md)
 * [Running in Production](./docs/tutorials/running-in-production.md)
+* [Adding Storage Adapter](./docs/tutorials/add-storage-adapter.md)
 
 ## Other Ways to Help