make shell scripts more POSIX-compatible, and use tabs instead of spaces

usr/bin/git-leaderboard

@@ -1,17 +1,11 @@
-#!/bin/bash
+#!/usr/bin/sh
 if [ -z ${1+x} ]; then
-    echo -e "\033[91mdidn't include a file exstension. (eg. \".cs\")"
-    exit -1
+	printf "\033[91mdidn't include a file exstension. (eg. \".cs\")\n"
+	exit 1
 fi
 
 # get all the files with the file extension
 git ls-files | grep -E ".*\\$1" |
-
-# run git blame on each file, which shows the commit for each line
-xargs -n 1 git blame --line-porcelain |
-
-# aquire the authors of this output and sort it
-grep "^author " | sort |
-
-# count all the unique authors and sort by number
-uniq -c | sort -nr
+	xargs -n 1 git blame --line-porcelain | # run git blame on each file, which shows the commit for each line
+	grep "^author " | sort |                # aquire the authors of this output and sort it
+	uniq -c | sort -nr                      # count all the unique authors and sort by number