Add stack's methods signature

Also fixed some typos in comments or define.

README.md

@@ -17,6 +17,6 @@ Use this command to compile the project.
 Use this command to clean the project.
 
 ### Run the tests
-> `make run_tests`
+> `make test`
 
 Use this command to start the tests.
\ No newline at end of file

main.c

 /* Author : Dario GENGA
- * Date : 16.11.2021
- * Description : Library to manipulate the pile
+ * Date : 23.11.2021
+ * Description : Library to manipulate the stack
  */
 
 #include <stdio.h>

stack.c

 /* Author : Dario GENGA
- * Date : 16.11.2021
+ * Date : 23.11.2021
  * Description : Library to manipulate the stack
  */
 

stack.h

 /* Author : Dario GENGA
- * Date : 16.11.2021
+ * Date : 23.11.2021
  * Description : Library to manipulate the stack
  */
-#ifndef _PILE_H
-#define _PILE_H
+#ifndef _STACK_H
+#define _STACK_H
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdbool.h>
 
+typedef struct _stack {
+    int size;
+    int top;
+    int *data;
+} stack;
+
+void stack_init(stack *s, int size);
+bool stack_is_empty(stack s);
+void stack_push(stack *s, int val);
+void stack_pop(stack *s, int *val);
+void stack_peek(stack s, int *val);
+void stack_destroy(stack *s);
 
 #endif
\ No newline at end of file

test.c

 /* Author : Dario GENGA
- * Date : 16.11.2021
- * Description : Manipulate matrix
+ * Date : 23.11.2021
+ * Description : Library to manipulate the stack
  */
 #include "stack.h"
 #include <assert.h>