title: Rails bootstrap gem import vs require
body: <p>I wanted to use in my rails project bootstrap framework. I used this github repository/instruction to do it: <a href="https://github.com/twbs/bootstrap-rubygem" rel="nofollow noreferrer">https://github.com/twbs/bootstrap-rubygem</a>.
  In the instruction it is underlined that I need to change my application.css extension to css.scss and use only import statements (delete all: //= require). How can I include in my application other css files? With require I could simply type //= require tree . but in this case I have no idea what to do.</p>