add X to Anna Docheva line (#603)

Co-authored-by: Anna Docheva <annie.docheva@icloud.com>

Author: annadocheva17

students.txt

@@ -21,7 +21,7 @@ Descazeaud	Lucien
 Despréaux	Maxime     
 Dhoowooah	Hitaishi     
 Dias Pinto Alfonso	Martin     
-Docheva	Anna     
+Docheva	Anna  X
 Dreik	Gabriel     
 Du	Jing     
 El Bakouri	Samy