Exercise 7.1 (lettercount.py, design). Before attempting to program lettercount.py, create a file called design that includes some analysis on how you think the problem will be solved. Examples include: a flowchart of events in the program, pseudocode, or a step by step process written in plain english. If you choose to scan your design please make sure that it is legible. Next write a program that reads in a string on the command line and returns a table of the letters of the alphabet in alphabetical order which occur in the string together with the number of times each letter occurs. Case should be ignored. A sample run of the program would look this: 1 Enter some letters >>> The cat in the hat 2 a 2 3 c 1 4 e 2 s h 3 s t 4 This should involve writing a function called count_letters that takes in a string and returns a dictionary with these letters and counts