I'm really impressed with the readme file in this repository. Its a master class in effective documentation. Just look at the structure:

- 1-2 sentence summary of the project

- History (why we built this and didn't just use existing tools)

- What we've built, including what it does and how it compares to other tools (rsync in this case).

- How to install and use it

And the whole thing is full of images and animations showing the tool in action, and explaining enough of its internals.

I consider myself good at documentation, but I'm taking notes. This is excellent.