Addeds docs to tokenize

#include "tokenize.h"

/// Takes in the user input and tokenizes it

///

/// \param string user input

/// \param output

/// \return number of tokens

int tokenize(char *string, char **output) {

    // Make strtok thread safe

    char *strtok_save;

    // Our Delimiter is a space

    char *del = " ";

    // First call is special

    output[0] = strtok_r(string, del, &strtok_save);

    char *token = output[0];

    // Number of tokens is one

    int i = 1;

    while (token != NULL) {

        // String is NULL to keep getting tokens from the string pass in the first call of strtok_r

        token = strtok_r(NULL, del, &strtok_save);

        // Set the output

        output[i] = token;

        i++;

    }