use await in mongoose code example

Example: node js mongoose async await

const connectToDb = async () => {
  try {
    await mongoose.connect(<connection_string>, {
      useNewUrlParser: true,
      useUnifiedTopology: true,
      useCreateIndex: true,
    });
    console.log("Db connection success");
  } catch (err) {
    console.log(err.message);
    process.exit(1)
  }
};