Doc updation needed

[aj07]

Codes and steps mentioned on link https://docs.nearprotocol.com/docs/tutorials/zero-to-hero isn't matching with wallet integration code. ?

Also, while describing the code ... lets take example src-->main.js
it would be nice to describe all the code at one place rather then in bits after every another file.
finding the right place to make changes in the code would be easy :)