Update ReadMe

Author: damilola-paystack

.DS_Store

@@ -1,7 +1,7 @@
 # Paystack OpenAPI Specification
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 
-The OpenAPI specification for the Paystack API
+The OpenAPI specification for the [Paystack API](https://paystack.com/docs/api).
 
 ## Getting Started
 The [OpenAPI specification](https://swagger.io/specification/) provides another alternative to test the Paystack API.
@@ -12,12 +12,19 @@ You can download the specification and make use of it on:
 ## Components
 There are three main folders of interest in this repo:
 - `main`: This contains a comprehensive specification of the Paystack API:
-  - resources: This contains individual endpoints in each API category
-  - responses: This contains the models for responses
-  - schemas: This contains models for each endpoint 
-  - paystack.yml: This is the entry point for all components
-- `dist`: In order to allow making use of the specification, we built a single file from all components in `main` folder.
-- `sdk`: This is a single file specification being used to client library generation. It contains just enough parameters for our client libraries.
+  - `resources`: This contains individual endpoints in each API category
+  - `responses`: This contains the models for responses
+  - `schemas`: This contains models for each endpoint 
+  - `paystack.yml`: This is the entry point for all components
+- `dist`: Not all OpenAPI readers can read from different file sources, so we built a single file from all the components in the `main` directory.
+- `sdk`: This is a single file specification being used for client library generation. It contains just enough parameters for our client libraries.
+- `use_cases`: This is a collection of specifications containing APIs for common use cases of the Paystack API. For example, the `wallet.yaml` contains the APIs needed to build a wallet feature into your application. The specifications in this directory are used to create the collections in our [Postman Workspace](https://www.postman.com/paystack-developers?tab=collections).
+
+## Contributing
+Here are some of the ways to contribute to this repository:
+- Create a use case
+- Raise an issue
+- Suggest an improvement
 
 ## Issues
 Kindly [open an issue](https://github.com/PaystackOSS/openapi/issues) if you discover any bug or have problems using this library.