Update application.properties

Changed the variable values to use optional environment values instead when present.

src/main/resources/application.properties

@@ -2,16 +2,16 @@ spring.application.name=smart-inventory
 
 # Server Port Configuration.
 # The default server port is 8080.
-server.port=9090
+server.port=${PORT:9090}
 
 # Database Configuration.
 # PostgreSQL.
-spring.datasource.url=jdbc:postgresql://localhost:5432/the_review_room
-# For WSL, use postgres.
+spring.datasource.url=${SPRING_DATASOURCE_URL:jdbc:postgresql://localhost:5432/the_review_room}
+# For WSL, use postgres. 
 # For Mac, use your Mac username.
-spring.datasource.username=postgres
+spring.datasource.username=${SPRING_DATASOURCE_USERNAME:postgres}
 # Password can be blank if we set it to trust in pg_hba.conf.
-spring.datasource.password=
+spring.datasource.password=${SPRING_DATASOURCE_PASSWORD:}
 
 # Database platform to use.
 spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect
@@ -69,6 +69,6 @@ springdoc.swagger-ui.path=/swagger-ui.html
 # [email protected]@
 # Set the default active profile.
 # Use the command to activate: mvn spring-boot:run -Dspring.profiles.active=development.
-spring.profiles.active=development
+spring.profiles.active=${SPRING_PROFILES_ACTIVE:development}
 # Set the default default profile. This is the profile that is used on any bean if you don't specify the @Profile annotation to be a certain profile.
 # spring.profiles.default=development