docs(APIAttachment): clarify title field distinction from filename (#1450)

Co-authored-by: Jiralite <33201955+Jiralite@users.noreply.github.com>
Co-authored-by: almeidx <42935195+almeidx@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

Author: 3 people

deno/payloads/v10/message.ts

@@ -810,7 +810,10 @@ export interface APIAttachment {
 	 */
 	filename: string;
 	/**
-	 * The title of the file
+	 * The original filename of the upload with special characters preserved
+	 *
+	 * This will be present when the filename contains special characters (e.g. Cyrillic),
+	 * in which case the `filename` field will be a sanitized version without those characters
 	 */
 	title?: string;
 	/**

deno/payloads/v9/message.ts

@@ -805,7 +805,10 @@ export interface APIAttachment {
 	 */
 	filename: string;
 	/**
-	 * The title of the file
+	 * The original filename of the upload with special characters preserved
+	 *
+	 * This will be present when the filename contains special characters (e.g. Cyrillic),
+	 * in which case the `filename` field will be a sanitized version without those characters
 	 */
 	title?: string;
 	/**