ci: add milestone action

.github/workflows/milestone.yml

@@ -0,0 +1,27 @@
+name: Generate and Publish Milestone Document
+
+on:
+  workflow_dispatch:
+  issues:
+    types: [opened, closed, edited, demilestoned, milestoned, reopened, assigned, unassigned, labeled, unlabeled]
+  pull_request:
+    types: [opened, closed, edited, demilestoned, milestoned, reopened, assigned, unassigned, labeled, unlabeled]
+
+jobs:
+  milestone:
+    name: Generate and Publish Milestone Document
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Milestone Documentation Generator
+        uses: ory/milestone-action@v0.0.8
+        with:
+          GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+          outputFile: docs/docs/milestones.md
+      - name: Commit Milestone Documentation
+        uses: EndBug/add-and-commit@v4.4.0
+        with:
+          message: "autogen(docs): update milestone"
+          author_name: aeneasr
+          author_email: "3372410+aeneasr@users.noreply.github.com"