Update issue template (open-mmlab#417)

* update template

* update emoji

Author: dreamerlin

.github/ISSUE_TEMPLATE/error-report.md

@@ -8,6 +8,7 @@ assignees: ''
 ---
 
 Thanks for your error report and we appreciate it a lot.
+If you feel we have help you, give us a STAR! :satisfied:
 
 **Checklist**
 1. I have searched related issues but cannot get the expected help.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -7,6 +7,9 @@ assignees: ''
 
 ---
 
+Thanks for your feature request and we will review and plan for it when necessary.
+If you feel we have help you, give us a STAR! :satisfied:
+
 **Describe the feature**
 
 **Motivation**

.github/ISSUE_TEMPLATE/reimplementation_questions.md

@@ -7,6 +7,8 @@ assignees: ''
 
 ---
 
+If you feel we have help you, give us a STAR! :satisfied:
+
 **Notice**
 
 There are several common situations in the reimplementation issues as below