[ADD] linux build

Author: ktx-mega

.github/workflows/dotnet-desktop.yml

@@ -25,7 +25,11 @@ jobs:
             artifact_name: winBuild.exe
             asset_name: windows-x64
             runtime: win-x64
-
+          - target: ubuntu-latest
+            os: ubuntu-latest
+            artifact_name: ubuntuBuild
+            asset_name: linux-x64
+            runtime: linux-x64
     steps:
      # Checkout the repo
      - uses: actions/checkout@v2