yttyx: convert to utf-8 encoding (#20672)

keyboards/atreus/keymaps/yttyx/README.md

@@ -33,7 +33,7 @@ sudo avrdude -p atmega32u4 -c avr109 -U flash:w:atreus_yttyx.hex -P /dev/ttyACM0
 
 
     .--------.-------.-------.-------.-------.                              .------.-------.-------.-------.------.
-    | Esc    |       |       |       | RS    |                              | |    | /     | ^     | £     |  ~   |
+    | Esc    |       |       |       | RS    |                              | |    | /     | ^     | £     |  ~   |
     |--------+-------+-------+-------+-------|                              |------+-------+-------+-------+------|
     | Tab    |       |       |       |       |                              | &    | \     | `     | $     | Ent  |
     |--------+-------+-------+-------+-------|                              |------+-------+-------+-------+------|