Fidel Docs reference to Merchant IDs lacks reference

[taboca]

*This feedback is based on a first reading experience, when I found Fidel Docs as part of an interview process; I decided to annotate some points— things I may perceived as ambiguous. Keep in mind that it's my own view and not exactly a problem in the documentation. *

Problem

At https://docs.fidel.uk/programs/add-locations I felt that "Merchant IDs (MIDs)" was quite suddenly introduced. This may related to the case like #87. Maybe things related to app/dashboard/UI could be all linked or crossreferenced, I don't know. Anyway visiting the docs and suddenly facing this term was a bit hard for a beginner-developer trying to grasp docs.