- replaced git submodule by command

Author: baywet

.github/workflows/dotnetcore.yml

@@ -14,7 +14,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Checkout submodules
-      uses: textbook/git-checkout-submodule-action@master
+      run: git submodule init
     - name: Setup .NET Core
       uses: actions/setup-dotnet@v1
       with: