modify the template title (#6589)

Author: Sunny6889

.github/ISSUE_TEMPLATE/ask-a-question.md

@@ -1,7 +1,7 @@
 ---
 name: Ask a question
 about: Something is unclear or needs clarification
-title: '[QUESTION] '
+title: '[Question]'
 labels: 'type:docs'
 assignees: ''
 

.github/ISSUE_TEMPLATE/report-a-bug.md

@@ -1,7 +1,7 @@
 ---
 name: Report a bug
 about: Create a report to help us improve
-title: '[BUG] '
+title: '[Bug]'
 labels: 'type:bug'
 assignees: ''
 

.github/ISSUE_TEMPLATE/request-a-feature.md

@@ -1,7 +1,7 @@
 ---
 name: Request a feature
 about: Suggest an idea for this project
-title: '[FEATURE] '
+title: '[Feature]'
 labels: 'type:feature'
 assignees: ''