Improving issue templates. (#877)

making ordering explicit, and disabling blank issue submission to force
triage label to be set.

.github/ISSUE_TEMPLATE/30-blank.yaml

@@ -0,0 +1,10 @@
+name: Blank Issue
+description: Don’t see your issue here? Open a blank issue.
+labels: [triage]
+body:
+- type: textarea
+  attributes:
+    label: Description
+    description: Please describe your issue.
+  validations:
+    required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -1,3 +1,4 @@
+blank_issues_enabled: false
 contact_links:
 - name: 💬 Community Feedback (Canny)
   url: https://feedback.secondlife.com