chore: sms 서비스 관련 설정 추가(#28)

sms 서비스를 이용하기 위해 필요한 설정들 추가

be/src/main/resources/application.yml

@@ -1,18 +1,28 @@
 spring:
   config:
     import: "classpath:application.properties"
+
   datasource:
     url: ${DATABASE_URL}
     username: ${DATABASE_USERNAME}
     password: ${DATABASE_PASSWORD}
     driver-class-name: com.mysql.cj.jdbc.Driver
+
   jpa:
     properties:
       hibernate:
         show_sql: true
         format_sql: true
+
   mail:
     host: smtp.gmail.com
     port: 587
     username: ${GOOGLE_SMTP_USERNAME}
     password: ${GOOGLE_SMTP_PASSWORD}
+
+  sms:
+    api_key: ${SMS_API_KEY}
+    api_secret: ${SMS_API_SECRET}
+    provider: https://api.coolsms.co.kr
+    sender: ${SMS_SENDER}
+