Allow to choose sub-folder as saving route

[suzyvaque]

Is your feature request related to a problem? Please describe.
It would be nice to save results to a sub-folder of my repository.

Describe the solution you'd like
Currently I modified the const url values in leetcode.js file to
.../contents/${subfolders}/${difficulty}/...
then loaded it to chrome extension. (If anyone needs it, this file is uploaded in my forked repo.)
This manual configuration works fine personally and I believe there are people with similar implementations, but it would be more convenient if I could choose & alter this sub-folder route from the welcome.html directly.

Describe alternatives you've considered
N/A

Additional context
N/A