add image conversion for telegram

internal/memos/types.go

@@ -37,6 +37,24 @@ func (a Attachment) IsImage() bool {
 	return false
 }
 
+// IsVideo returns true if the attachment is a video.
+func (a Attachment) IsVideo() bool {
+	switch a.Type {
+	case "video/mp4", "video/quicktime", "video/webm", "video/mpeg":
+		return true
+	}
+	return false
+}
+
+// IsAudio returns true if the attachment is an audio file.
+func (a Attachment) IsAudio() bool {
+	switch a.Type {
+	case "audio/mpeg", "audio/ogg", "audio/wav", "audio/mp4", "audio/aac":
+		return true
+	}
+	return false
+}
+
 // UID extracts the uid part from "attachments/{uid}".
 func (a Attachment) UID() string {
 	const prefix = "attachments/"