ci: add project-add.yml

.github/workflows/project-add.yml

@@ -0,0 +1,21 @@
+name: Add issues and PRs to Sia project
+
+on:
+  issues:
+    types:
+      - opened
+  pull_request:
+    types:
+      - opened
+
+jobs:
+  add-to-project:
+    name: Add issue to project
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/[email protected]
+        with:
+          # You can target a project in a different organization
+          # to the issue
+          project-url: https://github.com/orgs/SiaFoundation/projects/5
+          github-token: ${{ secrets.PAT_ADD_TO_PROJECT }}