Update issue templates

Author: jim-parry

.github/ISSUE_TEMPLATE/bug_report.md

@@ -2,7 +2,7 @@
 name: Bug report
 about: Create a report to help us improve
 title: 'Bug: '
-labels: ''
+labels: bug
 assignees: ''
 
 ---

.github/ISSUE_TEMPLATE/planned-work.md

@@ -0,0 +1,10 @@
+---
+name: Planned work
+about: Approved work planning
+title: 'Dev: '
+labels: dev
+assignees: ''
+
+---
+
+Repo maintainers will create "issues" for planned work, so it can be tracked.

.github/ISSUE_TEMPLATE/support-question.md

@@ -0,0 +1,11 @@
+---
+name: Support question
+about: How to ask a support question
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+Please ask support questions on our [forum](https://forum.codeigniter.com/forum-30.html).
+We use github issues to track bugs and planned work.