Removing a terribly offensive sentence in the readme

Dependencies

• [2] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).

Change contents

• replacement in README.md at line 7
  [2.1026979]→[2.1026979:1027254](∅→∅)
  − The license is GPL-2.0, meaning in particular that you can't relicense it under an incompatible license. Also, if you decide to make your own version of Pijul after looking at this code, this *is* derived work under copyright law, and you still have to respect this license.
  [2.1026979]

  [2.1027254]
  + The license is GPL-2.0.