feat: add PR size labeler workflow

.github/config/size-labels.yml

@@ -0,0 +1,18 @@
+labels:
+  - name: teeny
+    max_lines: 10
+
+  - name: small
+    max_lines: 100
+
+  - name: medium
+    max_lines: 500
+
+  - name: large
+    max_lines: 2000
+
+  - name: oh lawd he comin
+    message: |
+      This PR exceeds the recommended size of 2000 lines.
+      Please make sure you are NOT addressing multiple issues with one PR.
+      Note this PR might be rejected due to its size.

.github/workflows/pr-size-labeler.yml

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+name: PR Size Labeler
+
+on:
+  pull_request:
+    types: [ opened, reopened, synchronize ]
+
+jobs:
+  label-pr-size:
+    name: Apply Size Label
+    permissions:
+      contents: read
+      pull-requests: write
+    runs-on: ubuntu-latest
+    steps:
+      - name: Apply Size Label
+        uses: lukas-kuntze/devx-action-pr-size-labeler@v1
+        with:
+          config_file: .github/config/size-labels.yml
+          github_token: ${{ secrets.GITHUB_TOKEN }}