Fix split space label in matrix_diagram

Co-authored-by: Duncan Sutherland <dunk2k_2000@hotmail.com>

keyboards/zeix/singa/kohaku/matrix_diagram.md

@@ -25,6 +25,6 @@
 │80  │90  │81  │92         │83  │94     │85  │95  │ Split Space (Left 2.75u)
 └────┴────┴────┴───────────┴────┴───────┴────┴────┘
 ┌────┬────┬────┬───────┬────┬───────────┬────┬────┐
-│80  │90  │81  │92     │83  │94         │85  │95  │ Split Space (Left 2.75u)
+│80  │90  │81  │92     │83  │94         │85  │95  │ Split Space (Left 2.25u)
 └────┴────┴────┴───────┴────┴───────────┴────┴────┘
 ```