feat: articles format option with markdown new default

internal/domain/article/bodyFormat.go

@@ -0,0 +1,32 @@
+package article
+
+import (
+	"errors"
+	"strings"
+)
+
+var ErrUnsupportedBodyFormat = errors.New("unsupported body format")
+
+type BodyFormat string
+
+const (
+	BodyFormatMarkdown BodyFormat = "markdown"
+	BodyFormatHTML     BodyFormat = "html"
+	BodyFormatJSON     BodyFormat = "json"
+)
+
+func ParseBodyFormat(value string) (BodyFormat, error) {
+	switch strings.ToLower(value) {
+	case "", string(BodyFormatMarkdown):
+		return BodyFormatMarkdown, nil
+	case string(BodyFormatHTML):
+		return BodyFormatHTML, nil
+	case string(BodyFormatJSON):
+		return BodyFormatJSON, nil
+	}
+	return "", ErrUnsupportedBodyFormat
+}
+
+type BodyRenderer interface {
+	Render(html string, format BodyFormat) (string, error)
+}