This is exactly it. The way to think about it is that smart contracts are effectively server-side code that is specialized to run on blockchains. They use many of the same building blocks and can often be reused. When I want to build Auth in Nodejs, I might use Passport.js, and I often use Express.js. Often I'll use mongoose.js as well. That's effectively what we're providing with cookbook, a way to find and utilize solidity packages created by the community.