Add a matrix factorization in the manner of federated learning example#341

LittleWat wants to merge 1 commit intoOpenMined:foundations-of-private-computationOpenMined/courses:foundations-of-private-computationfrom

LittleWat:fl-matrix-factorization-exampleLittleWat/courses:fl-matrix-factorization-exampleCopy head branch name to clipboard