feat: support .NET

Signed-off-by: Olli Janatuinen <olli.janatuinen@gmail.com>

pkg/universe.dagger.io/x/olli.janatuinen@gmail.com/dotnet/image.cue

@@ -0,0 +1,20 @@
+package dotnet
+
+import (
+	"universe.dagger.io/docker"
+)
+
+// .NET image default version
+_#DefaultVersion: "6.0"
+
+// Pull a dotnet base image
+#Image: {
+	version: *_#DefaultVersion | string
+	docker.#Build & {
+		steps: [
+			docker.#Pull & {
+				source: "mcr.microsoft.com/dotnet/sdk:\(version)-alpine"
+			},
+		]
+	}
+}