How can we take a website into our code, withput going to that site

Answer 1

Technically speaking we can't. You explicitly wrote "without going to that site", even if you only display the site content in a frame, you will still have to go to the site to send a fetch request for the content, so "without ever going to that site", it is just not possible.

Answer 2

Probably you can do like this, worls in Chrome :
view-source:https://someurl