Prompts for inputs and reads replies.
Does not actually count any letters yet.
There is no break from the infinite loop (other than control C)
count the number of letters
using method numTimesChrInStr but does not have any method of getting
out of the infinite loop.
Now works for the exercise sheet example.
Try documenting example output in asciidoc
rather than markdown as it is an easier markup language
where I can check markup before uploading. github seems to
handle it well (on another project).
document exercise 7 counting letters redux