fix: update description in meta description tag

Author: kkweon

client/web/index.html

@@ -15,7 +15,7 @@
 
   <meta charset="UTF-8">
   <meta content="IE=Edge" http-equiv="X-UA-Compatible">
-  <meta name="description" content="A new Flutter project.">
+  <meta name="description" content="PR12er는 PR-12를 좀더 쉽게 보기 위한 코딩냄비의 그룹 프로젝트입니다.">
 
   <!-- iOS meta tags & icons -->
   <meta name="apple-mobile-web-app-capable" content="yes">