fix: add baseurl variable to config & use it before getting routes

[oskar-gmerek]

This is simply temporary solution for working with custom baseUrl. (#88 #89)

For now users can define baseUrl in vantage config.

But in the future that should be automagically checked from tsconfig.json and next.config.js

Example:
"baseUrl": "./src"

I don't know if it's possible to contribute for docs.

[mnoah1]

Thank you for the submission. I just approved #91 which just uses a true/false to specify whether to check for pages in src or the project root. It seems that a true/false should work here as Next only officially supports putting pages either in the root or in /src. Do you feel there is a use case where the use should be able to specify something other than src?

[oskar-gmerek]

@mnoah1 Not sure about other cases, I just think it is more semantic to define it as string if it is string in tsconfig. Anyway I strongly feel that variable should be reading value from tsconfig and next.config as long as you targeting wider with that project.