Create auto-update.yml

Automatically push updates from Pokerogue's main repo to this one's Automerge repo, so I can add them (will change to pushing to main if it doesn't attempt to resolve conflicts by itself)

.github/workflows/auto-update.yml

@@ -0,0 +1,31 @@
+name: Update Fork
+
+on:
+  schedule:
+    - cron: '0 0 * * *' # Runs every day at midnight
+  push:
+    branches:
+      - main
+
+jobs:
+  update-fork:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout fork
+        uses: actions/checkout@v2
+        with:
+          repository: PokeRogue-Projects/Pathing-Tool
+          ref: Automerge
+
+      - name: Add upstream
+        run: git remote add upstream https://github.com/pagefaultgames/pokerogue.git
+
+      - name: Fetch upstream
+        run: git fetch upstream
+
+      - name: Merge upstream changes
+        run: |
+          git checkout main
+          git merge upstream/main
+          git push origin Automerge