Link routines for global updates of weight changes.

Being able to tag routines as linked would be helpful for updates. For example, If a user has two routines - day 1 is done one way and day 2 in reverse. By linking when the user adjusts the weight for exercises in one it updates in all linked. Another example I have a light and heavy leg day (depending on time). Have to go in and adjust squat on both when I want to update the weights for reps. If they were linked I could do one and it would reflect in the other(s).