ci: add aoc badge

.github/workflows/badges.yml

@@ -0,0 +1,22 @@
+name: Update AoC Badges
+on:
+  schedule:
+    - cron: '6 5 1-25 12 *'                      # from the 1. December till 25. December every day at 5:06am (avoid load at full hours)
+
+  workflow_dispatch:
+
+jobs:
+  update:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: joblo2213/aoc-badges-action@v3
+        with:
+          userid: 648624
+          session: ${{ secrets.AOC_SESSION }}
+
+      - uses: stefanzweifel/git-auto-commit-action@v4
+        with:
+          commit_message: "chore: update AoC badge"
+          file_pattern: README.md

README.md

@@ -1,4 +1,5 @@
 [![ci](https://github.com/michaeladler/aoc-2023/actions/workflows/ci.yml/badge.svg)](https://github.com/michaeladler/aoc-2023/actions/workflows/ci.yml)
+![](https://img.shields.io/badge/stars%20⭐-34-yellow)
 
 # 🎄 Advent of Code 2023 Solutions 🎄