update/use .env port variable

.env.example

@@ -1,5 +1,5 @@
 mongoURI=mongodb://localhost:27017
 dbo=school
-PORT=8080
+PORT=8000
 SYSTEM_EMAIL=
 SYSTEM_PASSWORD=

main.go

@@ -1,7 +1,10 @@
 package main
 
 import (
+	"os"
+
 	"github.com/SowinskiBraeden/school-management-api/routes"
+	"github.com/joho/godotenv"
 
 	"github.com/gofiber/fiber/v2"
 	"github.com/gofiber/fiber/v2/middleware/cors"
@@ -16,5 +19,7 @@ func main() {
 
 	routes.Setup(app)
 
-	app.Listen(":8000")
+	godotenv.Load(".env")
+	port := os.Getenv("port")
+	app.Listen(":" + port)
 }