C - Static libraries

In this project, I learned what static libraries are and practiced creating and using them with ar, ranlib, and nm.

Tests ✔️

0. A library is not a luxury but one of the necessities of life
- libholberton.a: C Static library containing all the functions listed below:
  - int _putchar(char c);
  - int _islower(int c);
  - int _isalpha(int c);
  - int _abs(int n);
  - int _isupper(int c);
  - int _isdigit(int c);
  - int _strlen(char *s);
  - void _puts(char *s);
  - char *_strcpy(char *dest, char *src);
  - int _atoi(char *s);
  - char *_strcat(char *dest, char *src);
  - char *_strncat(char *dest, char *src, int n);
  - char *_strncpy(char *dest, char *src, int n);
  - int _strcmp(char *s1, char *s2);
  - char *_memset(char *s, char b, unsigned int n);
  - char *_memcpy(char *dest, char *src, unsigned int n);
  - char *_strchr(char *s, char c);
  - unsigned int _strspn(char *s, char *accept);
  - char *_strpbrk(char *s, char *accept);
  - char *_strstr(char *haystack, char *needle);
- holberton.h: Header file containing the prototypes of all functions included in libholberton.a.
1. Without libraries what have we? We have no past and no future
- create_static_lib.sh: Bash script that creates a static library called liball.a from all the .c files in the current directory.