feat: add translate command

openai/prompts/prompts.go

@@ -0,0 +1,14 @@
+package prompts
+
+import "fmt"
+
+func General() string {
+	return "You are a helpful assistant."
+}
+
+func Translate(targetLang string) string {
+	return fmt.Sprintf(
+		"You are a helpful assistant. Your task is to help translate the following text to %s. You should not interpret the text. You should structure the translated text to look natural in native %s, while keeping the meaning unchanged.",
+		targetLang, targetLang,
+	)
+}