feat: completion command (#1157)

completion.go

@@ -0,0 +1,34 @@
+package task
+
+import (
+	_ "embed"
+	"fmt"
+)
+
+//go:embed completion/bash/task.bash
+var completionBash string
+
+//go:embed completion/fish/task.fish
+var completionFish string
+
+//go:embed completion/ps/task.ps1
+var completionPowershell string
+
+//go:embed completion/zsh/_task
+var completionZsh string
+
+func Completion(completion string) (string, error) {
+	// Get the file extension for the selected shell
+	switch completion {
+	case "bash":
+		return completionBash, nil
+	case "fish":
+		return completionFish, nil
+	case "powershell":
+		return completionPowershell, nil
+	case "zsh":
+		return completionZsh, nil
+	default:
+		return "", fmt.Errorf("unknown shell: %s", completion)
+	}
+}