Adding some instructions in README file

bash_array_jobs/README.md

 # Content #
 
-* prep_env: 
-
+* prep_env:  
 An executable to create test environment to run the job scripts on.
 
 Usage: ./prep_env {seq,rand.diff}
 
-seq: Create a test_dir with sequential file names.
-rand: Create a test_dir with random file names.
+seq: Create a test_dir with sequential file names.  
+rand: Create a test_dir with random file names.  
 diff: Create a test_dir with random sub-directory names, and a file 'test' in each directory.
 
 
-* clean_env:
-
+* clean_env:  
 An executable to remove all the files/directories from your current directory, except the ones originally present.
 
 Usage: ./clean_env
 
 
-* bash_parallel_script:
+* bash_parallel_script: