Update Jekyll diff action to allow targeting correct branch

Author: abkfenris

.github/workflows/jekyll-diff.yml

@@ -8,6 +8,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v1
-    - uses: David-Byrne/jekyll-diff-action@v1.2.0
+    - uses: David-Byrne/jekyll-diff-action@v1.3.0
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}