chore: label pull requests by changed files

.github/labeler.yml

@@ -0,0 +1,15 @@
+documentation:
+  - changed-files:
+      - any-glob-to-any-file:
+          - "**/*.md"
+
+dependencies:
+  - changed-files:
+      - any-glob-to-any-file:
+          - go.mod
+          - go.sum
+
+go:
+  - changed-files:
+      - any-glob-to-any-file:
+          - "**/*.go"

.github/workflows/pr-labels.yml

@@ -0,0 +1,19 @@
+name: PR Labels
+
+on:
+  pull_request_target:
+    types: [opened, synchronize, reopened]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  label-files:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/labeler@8558fd74291d67161a8a78ce36a881fa63b766a9
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          configuration-path: .github/labeler.yml