That same website has a guide to setting up a development environment for homebrew Switch software, as well:
https://switch.homebrew.guide/homebrew_dev/introduction.html
There isn't really an above-board way to publish software on Switch without an SDK. However, you can unlock the hardware to run Android or a (very fragile) version of Linux. There are also custom firmwares that let you create homebrew software for Nintendo's official software, but you'll be pretty limited there too.