Update jekyll.yml, on push to main (not master)

Author: Phu2

.github/workflows/jekyll.yml

@@ -9,7 +9,7 @@ name: Deploy Jekyll site to Pages
 on:
   # Runs on pushes targeting the default branch
   push:
-    branches: ["master"]
+    branches: ["main"]
 
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch: