이슈 템플릿 수정

.github/ISSUE_TEMPLATE.md

@@ -1,10 +1,13 @@
 ## Environment (환경)
-OS :
-Python version :
-openNAMU version :
-Skin : 
-Skin version : 
+* OS :
+* Python version :
+* openNAMU version :
+* Skin : 
+* Skin version : 
+
+<!-- 무언가 작동 안할 때는 캐시 초기화를 먼저 해보세요. -->
+<!-- Try initializing the cache first when something isn't working. -->
 
 ## Explanation (설명)
 
-## Screenshot (스크린샷)
+## Screenshot (스크린샷)