That is the getting started page. It lists multiple ways to get started. One of them is simply including the pre-built preact library with a <script> tag. After

That is the getting started page. It lists multiple ways to get started. One of them is simply including the pre-built preact library with a <script> tag. After that you can use h() to build elements - no build step required. I personally use preact over react because it's tiny - 3kb for the entire library.