letter_count
add letter_count programs

letter_count.c
    C file, simple program that counts the occurance of
    each letter from stdin
rand_letters.sh
    bash script that simply sorts letter_count.c output
Makefile
    Make file for letter_count.c with an unnecessary amount of gcc flags
rank_letters.sh now takes an arg for letter_count.c - if no arg, use stdin
rename Hangman.pl as hangman.pl
update freq
update server.js - change initial guesses back to 3
update README.md