Update repositories.txt (arduino#2624)

lucasdietrich · web-flow · commit d9bdbba57668 · 2023-03-25T15:50:08.000Z
diff --git a/repositories.txt b/repositories.txt
@@ -5687,3 +5687,4 @@ https://gitlab.com/yesbotics/simple-serial-protocol/simple-serial-protocol-ardui
 https://gitlab.com/zaber-core-libs/zaber-ascii-for-arduino
 https://gitlab.com/zaber-core-libs/zaber-binary-for-arduino
 https://github.com/MRROBO28/GSheet32
+https://github.com/lucasdietrich/AVRTOS
