Update repositories.txt

Author: Frederik-Eberhard

repositories.txt

@@ -422,7 +422,7 @@ https://github.com/Tinyu-Zhao/PCA9554
 https://github.com/Tinyu-Zhao/FFT
 https://github.com/Tinyu-Zhao/TFTTerminal
 https://github.com/chochain/nanoFORTH
-https://github.com/Frederik-Eberhard/Excelsior
+https://github.com/Excelsior-Robotics/Excelsior
 https://github.com/oguzkaganyaglioglu/PLCustomDevicesLibrary
 https://github.com/dimag0g/PPM-reader
 https://github.com/Mysues/ERO