updated readme

README.md

@@ -3,16 +3,27 @@ REST API for expense tracking and budgeting.
 
 ## Project setup
 ```bash
-$ npm install
+npm install
 ```
 
-## Compile and run the project
-Run local Postgres DB:
+## Run Locally
+By default, the API looks for a locally running Postgres instance, which can be satisfied by running the following container:
 ```bash
 docker run --name common-cents-db -e POSTGRES_USER=common-cents -e POSTGRES_PASSWORD=CommonCents_123! -p 5432:5432 -d postgres
 ```
 
-Then run the API:
+Alternatively, a DB configuration can be provided through an environment file placed in the root directory (`common-cents-api/.env`):
+```text
+# .env
+DB_SYNC=true # should be false for production environment
+DB_HOST=localhost
+DB_PORT=5432
+DB_USER=common-cents
+DB_PASS=CommonCents_123!
+DB_NAME=common-cents
+```
+
+Once the DB is configured/running, the API can be started:
 ```bash
 npm run start:dev
 ```