add .dirmd and other metadata

internal/instructions/instructions.go

@@ -0,0 +1,41 @@
+package instructions
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const FileName = ".dirmd"
+
+func Read(rootDir string) (string, error) {
+	path := filepath.Join(rootDir, FileName)
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return "", nil
+		}
+		return "", err
+	}
+	return string(data), nil
+}
+
+func Format(content string) string {
+	if content == "" {
+		return ""
+	}
+	content = strings.TrimSpace(content)
+	if content == "" {
+		return ""
+	}
+	lines := strings.Split(content, "\n")
+	var sb strings.Builder
+	sb.WriteString("> Instructions:\n")
+	for _, line := range lines {
+		sb.WriteString("> ")
+		sb.WriteString(line)
+		sb.WriteString("\n")
+	}
+	sb.WriteString("\n")
+	return sb.String()
+}