Add Measurements task 2.1 to Distinguishing States Kata

[JPark1023]

Added Common.qs, media folder, zero-plus folder containing task and updated index

Resolves part of #1185

[tcNickolas]

You'll also need to add this kata to the list at index.json temporarily, so that CI builds validate it, and I'll remove it from the list before merging. I do this locally when testing this change, but it's better to let CI validate it as well

[JPark1023]

@microsoft-github-policy-service agree