How do I establish relations between existing tables

Is this the same question is this one:
Update relationships from CSV or Excel [May 15] ?

How do I interpret the status of this issue:

I dont know Github well enough but I guess its on the issue board?
But having a hard time understanding if its on hold or open or just gone, I cant find it on the issue board anymore?

Background: I have 10 years of data in a closed source Android app (Sailforms) with around 70 tables exported to csv, but some tables function as ‘pick-list’ or ‘filter’ values for other tables. My intention is to import the tables and then establish relationships between them one-by-one.