Disclaimer: I am relatively new to this. Feel free to use a tone you'd otherwise use to explain to a 10yr old.

I am trying to run a rails app on docker. I came across permission errors while I trying to edit some of the files. After a couple of searches, I found out it is because docker, by default, creates files as root. I have been reading for a while now and I can't, for the life of me seem to understand how to implement USER instruction as recommended in the docker documentation.
Here's a link to my dockerfile https://github.com/Melvin1Atieno/....