In my experience and my own repositories -- informed by my experiences as an software user from a Global Majority country for about 35+ years, especially back in the day when software used to come only floppy disks or CDs --, I have readme files with their names translated.

So for example, for README.md, we would have:

• for pt (Portuguese): LEIAME.md
• for es (Spanish): LEAME.md
• for fr (French): LISEZMOI.md

And so forth.

And it makes sense, because you want your READER, not a software tools, to see it and grasp at a glance that they should READ(ME) that file, right?