Program finished

A pair of functions that cache the inverse of a matrix:
makeCacheMatrix
cacheSolve

Added more comments to bring clarity to the program

Should be run in the command line/terminal this way:

#1. pass a square matrix to makeCacheMatrix (example:
A=matrix(c(1,2,3,4), nrow=2, ncol=2)

#2 cache the inverse with cacheSolve(A)

#3 access the cached inverse with cacheSolve(A)