Rename default branch to "main" (#16)

Author: omus

.github/workflows/CI.yml

@@ -1,11 +1,11 @@
 ---
 name: CI
-# Run on master, tags, or any pull request
+# Run on default branch, tags, or any pull request
 on:
   schedule:
     - cron: "0 2 * * *"  # Daily at 2 AM UTC (8 PM CST)
   push:
-    branches: [master]
+    branches: [main]
     tags: ["*"]
   pull_request:
 jobs: