Update index.md with correct role definition name (#825)

Docs/index.md

@@ -52,7 +52,7 @@ EPAC is designed for medium and large organizations with a larger number of Poli
 
 ## Deployment Scripts
 
-Three deployment scripts plan a deployment, deploy Policy resources, and Role Assignments respectively as shown in the following diagram. The solution consumes definition files (JSON and/or CSV files). The planning script (`Build-DeploymentPlan`) creates plan files (`policy-plan.json` and `roles-plan.json`) to be consumed by the two deployment scripts (`Deploy-PolicyPlan` and `Deploy-RolesPlan`). The scripts require `Reader`, `Resource Policy Contributor` and `Role Based Access Administrator` privileges respectively as indicated in blue text in the diagram. The diagram also shows the usual approval gates after each step/script for prod deployments.
+Three deployment scripts plan a deployment, deploy Policy resources, and Role Assignments respectively as shown in the following diagram. The solution consumes definition files (JSON and/or CSV files). The planning script (`Build-DeploymentPlan`) creates plan files (`policy-plan.json` and `roles-plan.json`) to be consumed by the two deployment scripts (`Deploy-PolicyPlan` and `Deploy-RolesPlan`). The scripts require `Reader`, `Resource Policy Contributor` and `Role Based Access Control Administrator` privileges respectively as indicated in blue text in the diagram. The diagram also shows the usual approval gates after each step/script for prod deployments.
 
 ![image.png](Images/epac-deployment-scripts.png)