Actions: Automatically add language-specific labels to pull requests.

.github/labeler.yml

@@ -0,0 +1,23 @@
+C++:
+  - cpp/**/*
+  - change-notes/**/*cpp*
+
+C#:
+  - csharp/**/*
+  - change-notes/**/*csharp*
+
+Java:
+  - java/**/*
+  - change-notes/**/*java.*
+
+JS:
+  - javascript/**/*
+  - change-notes/**/*javascript*
+
+Python:
+  - python/**/*
+  - change-notes/**/*python*
+
+documentation:
+  - **/*.qhelp
+  - **/*.md

.github/workflows/labeler.yml

@@ -0,0 +1,11 @@
+name: "Pull Request Labeler"
+on:
+- pull_request
+
+jobs:
+  triage:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/labeler@v2
+      with:
+        repo-token: "${{ secrets.GITHUB_TOKEN }}"