Add issue handler workflow

- Handle triage for new issues
- Handle backport issues

Author: jvalkeal

.github/workflows/issue-handler.yml

@@ -0,0 +1,40 @@
+name: Issue Handler
+
+on:
+  workflow_dispatch:
+  issues:
+    types: [opened, labeled, unlabeled]
+
+jobs:
+  labeler:
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: Handle Issues
+      uses: jvalkeal/[email protected]
+      with:
+        token: ${{ secrets.GITHUB_TOKEN }}
+        config: >
+          {
+            "data": {
+              "team": ["jvalkeal"]
+            },
+            "recipes": [
+              {
+                "name": "Mark new issue to get triaged",
+                "type": "ifThen",
+                "if": "isAction('opened') && !dataInArray('team', actor)",
+                "then": "labelIssue(['status/need-triage'])"
+              },
+              {
+                "name": "Manage backport issues",
+                "type": "manageBackportIssues",
+                "whenLabeled": "labeledStartsWith(['branch/'])",
+                "whenUnlabeled": "labeledStartsWith(['branch/'])",
+                "whenLabels": "labelsContainsAny(['for/backport'])",
+                "fromLabels": "labeledStartsWith(['branch/'])",
+                "additionalLabels": "'type/backport'",
+                "body": "'Backport #' + number"
+              }
+            ]
+          }