Update README.md

 A simple program that takes a file called rspv.txt as input and displays the number of people
#  attending, not attending and yet to reply
#.
#  In order for the program to work the following pre-condition must be met
#
#   1)  The file name must be called rspv.txt
#   2)  The file must not be empty at least a minimum of one name must be in the file.
#   3)  The data in the file must be in the form of <name surname-response> separated by 
#         a comma if there are more then one grouping of names.
#
#   4) The response must either be 'yes' or 'no' or 'not replied'
#
#
#  If none of these pre-condition are met the program will not start, but politely inform you 
#  on how to solve the problem right before exiting.
#
#  If all pre-condition are met the information is then loaded into memory and the following
#   information can optionally be displayed to the user :
#    
#        1) Number of people attending Shannon Wedding
#        2) Number of people not attending Shannon weeding
#        3) Those who have yet to replied all in alphabetical order.
#
#      The program also includes a menu that allows the user of the program:
#            1) To directly added names to the rsvp.txt text
#            2) To look up names of guests who are attending, not attending or those who have not yet replied
#
#  To use the program ensure that the following files are in the same directory
#           1)  create_data.py
#           2)  error.py
#           3) You can use your own text file as long as it is called rsvp.txt but providing
#                the data is entered in the way specified in the pre-condition above everything should run smoothly
#
#           4) Once every thing mention in step 1-3 are in the current working directory run the wedding_rsvp.py file
#