Thx fot your answer!
So that's my JSON file ->
https://gist.github.com/Biseamon/dad9e9c5b91b68d4caebcfa8af7a7eb8
I have done some changes in the code and seems that it works, however I don't know how to test it and see if it is not repeating its values. Also, it displays the poly lines on the map but only as straight lines, which is weird. ->
https://gist.github.com/Biseamon/ef5e4ff015ff5cec003f81e35be973c0
If you could show me how would you do your way I would highly appreciate that. You can show me using libraries, even though I am not familiar with them.
As per the name of the parser "prs", that is just for myself. Eventually I will change to something more comprehensive.