update readme

Author: surajit

readme.md

@@ -23,7 +23,7 @@ payment. The Organization makes the payment and a payment record is saved in the
    - pip install -r requirements.txt
    - create .env file and add the keys for env-example
    - alembic upgrade head (to migrate)
-   - uvicorn main:app --reload (to run server)
+   - uvicorn app:app --reload (to run server)
 
 # External Integrations