gnu.org/philosophy already defines in detail, less in detail, GNU can be defined like “a free-software OS project started by rms, who increasingly delegates on other hackers, and accept contributions”.
Then if you really want it self-contained, you copy/paste some of what’s already in /philosophy/free-sw… If you want more technical details (like “not made only of GNU software”), copy/pasting parts of /distros/free-distros and /s and that’s it… The rest is arbitrary recent addition by some hackers, that’s why it doesn’t go further.
