enhance issue_template (#837)

.github/ISSUE_TEMPLATE/BUG_REPORT.md

@@ -1,3 +1,8 @@
+---
+name: Bug Report
+labels: bug
+about: If something isn't working as expected.
+---
 
 # What did you do? (required. The issue will be **closed** when not provided.)
 

.github/ISSUE_TEMPLATE/FEATURE_REQUEST.md

@@ -0,0 +1,9 @@
+---
+name: Feature Request
+labels: enhancement
+about: I have a suggestion (and might want to implement myself)!
+---
+
+<!--
+If this is a FEATURE REQUEST, request format does not matter!
+-->

.github/ISSUE_TEMPLATE/SUPPORT_QUESTION.md

@@ -0,0 +1,10 @@
+---
+name: Support Question
+labels: question
+about: If you have a question about Vuls.
+---
+
+<!--
+If you have a trouble, feel free to ask.
+Make sure you're not asking duplicate question by searching on the issues lists.
+-->