Fixed yaml syntax

.github/workflows/main.yml

@@ -35,10 +35,10 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - uses: actions/setup-dotnet@v1
-        with:
-            dotnet-version: | 
-                6.0.x
-                7.0.x
+      with:
+        dotnet-version: | 
+          6.0.x
+          7.0.x
     #  workaround for actions/setup-dotnet#155
     - name: Clear package cache
       run: dotnet clean LLamaSharp.sln && dotnet nuget locals all --clear