feat(message): added content_type to MessageAttachment

message.go

@@ -317,14 +317,15 @@ type MessageAllowedMentions struct {
 
 // A MessageAttachment stores data for message attachments.
 type MessageAttachment struct {
-	ID        string `json:"id"`
-	URL       string `json:"url"`
-	ProxyURL  string `json:"proxy_url"`
-	Filename  string `json:"filename"`
-	Width     int    `json:"width"`
-	Height    int    `json:"height"`
-	Size      int    `json:"size"`
-	Ephemeral bool   `json:"ephemeral"`
+	ID          string `json:"id"`
+	URL         string `json:"url"`
+	ProxyURL    string `json:"proxy_url"`
+	Filename    string `json:"filename"`
+	ContentType string `json:"content_type"`
+	Width       int    `json:"width"`
+	Height      int    `json:"height"`
+	Size        int    `json:"size"`
+	Ephemeral   bool   `json:"ephemeral"`
 }
 
 // MessageEmbedFooter is a part of a MessageEmbed struct.