Update docs

Author: ahmedxgouda

CONTRIBUTING.md

@@ -415,6 +415,30 @@ make test
 This command runs tests and checks that coverage threshold requirements are satisfied for both backend and frontend.
 **Please note your PR won't be merged if it fails the code tests checks.**
 
+### Setting Up e2e Testing Environment
+
+Follow these steps to setup your e2e testing environment:
+
+1. Run the e2e backend instance with the following command:
+
+   ```bash
+   make run-backend-e2e
+   ```
+
+2. Load the data into the e2e db with the following command (in another terminal session):
+
+   ```bash
+   make load-data-e2e
+   ```
+
+3. Now, you can stop the backend instance, and run the frontend e2e tests with the following command:
+
+   ```bash
+   make test-frontend-e2e
+   ```
+
+**Please note that you only need to do these steps once.**
+
 ### Test Coverage
 
 - There is a **minimum test coverage requirement** for the **backend** code -- see [pyproject.toml](https://github.com/OWASP/Nest/blob/main/backend/pyproject.toml).