Specific Pace for Running Plan & Percentage Pace

Feature Requests
7

Many threads are asking for it, the problem is it is not focused I guessed.
See also:

  1. https://forum.intervals.icu/t/when-editing-a-training-session-can-you-set-it-by-5k-race-pace
  2. Whether or not to support editing class schedules 5k, 10k, marathon pacing grammar - #3 by Pieter_Baele
  3. Build workouts using paces of fixed distances (eg. 1.2km @ 80% 5k pace)