Add Avg / Max HR to activity summary

[adrianhallnhsd]

Despite people asking Strava for it for years, activities like running and walking don't have the Avg/Max HR in teh activity summary on the top right.

Cycling has it, Yoga has it. But for some reason, Strava won't put it on other activities.

A great addition to your wonderful plugin would be to add those values to the ones that don't already have it on the overview page.