I thought it could be fun to include it in the documentation. Why not, after all. This is a good read. It turns out that I also used it for tests, if the editor behaves smoothly on this file I judge it fast enough.
Its probably for testing purpose. Its a big file of natural text so you can easily checks a lot of things with it and its a lot less boring than pages of lorem ipsum...
But, its funny that it is more than half of the full content in the git clone...
I am really curious about what the full text of Republic is doing here...