docs: add labels to github issue templates (#3573)

.github/ISSUE_TEMPLATE/1_Bug_report.md

@@ -1,6 +1,7 @@
 ---
 name: 🐛 Bug Report
 about: Report errors and problems
+labels: 'question'
 ---
 
 Are you experiencing an issue with...

.github/ISSUE_TEMPLATE/2_Failing_service_test.md

@@ -1,6 +1,7 @@
 ---
 name: 💚 Failing service test
 about: Note failing service tests
+labels: 'keep-service-tests-green'
 ---
 
 :clock11: **When did the problem start?**

.github/ISSUE_TEMPLATE/3_Badge_request.md

@@ -1,6 +1,7 @@
 ---
 name: 💡 Badge Request
 about: Ideas for new badges
+labels: 'service-badge'
 ---
 
 :clipboard: **Description**

.github/ISSUE_TEMPLATE/5_Support_question.md

@@ -1,6 +1,7 @@
 ---
 name: ❓ Support Question
 about: Ask a question about shields.io
+labels: 'question'
 ---
 
 :question: **Question**