delete Ruby illustrations

 images/Ruby_dark.png  | Bin 129919 -> 0 bytes
 images/Ruby_light.png | Bin 127739 -> 0 bytes
 2 files changed, 0 insertions(+), 0 deletions(-)

diff --git a/images/Ruby_dark.png b/images/Ruby_dark.png
deleted file mode 100644
index 71b86e8..0000000
Binary files a/images/Ruby_dark.png and /dev/null differ
diff --git a/images/Ruby_light.png b/images/Ruby_light.png
deleted file mode 100644
index 27d7538..0000000
Binary files a/images/Ruby_light.png and /dev/null differ