added xd75 to list in /keyboards

keyboards/readme.md

@@ -57,3 +57,4 @@ These keyboards are part of the QMK repository, but their manufacturers are not
 * [TheVan 44](/keyboards/tv44) — A 44-key staggered keybard by Evangs.
 * [WhiteFox](/keyboards/whitefox) — A 65% keyboard designed as a partnership by matt3o, Massdrop and Input Club
 * [Vision Division](/keyboards/vision_division) — Full Size / Split Linear Keyboard by IBNobody.
+* [XD75](/keyboards/xd75) — 15x5 ortholinear keyboard by XIUDI.