Update bug_report.md

- Add the bug label
- Make platform config more easy

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,8 +1,8 @@
 ---
 name: Bug report
 about: Create a report to help us improve
-title: ''
-labels: ''
+title: 'Bug:'
+labels: 'Bug'
 assignees: ''
 
 ---
@@ -23,16 +23,10 @@ A clear and concise description of what you expected to happen.
 **Screenshots**
 If applicable, add screenshots to help explain your problem.
 
-**Desktop (please complete the following information):**
+**Platform (please complete the following information):**
  - OS: [e.g. iOS]
  - Browser [e.g. chrome, safari]
  - Version [e.g. 22]
 
-**Smartphone (please complete the following information):**
- - Device: [e.g. iPhone6]
- - OS: [e.g. iOS8.1]
- - Browser [e.g. stock browser, safari]
- - Version [e.g. 22]
-
 **Additional context**
 Add any other context about the problem here.