function to read map keys

[AmmarHaddadi]

give it pointers to the 4 needed elements and it changes them to corresponding value from map file

• [ ] int number of lines on the map
• [ ] char "empty" character;
• [ ] char "obstacle" character;
• [ ] char "full" character.

[AmmarHaddadi]

@OUSS-ELK sat 3awd sawbha w 7edek dakshi li mtlob