chore: update github action merge workflow (#131)

Author: CloudyPadmal

.github/workflows/hardware-ci.yml

@@ -89,16 +89,16 @@ jobs:
           cd diff-img
           convert -colorspace gray front-layer.png old-front.png
           convert -colorspace gray bottom-layer.png old-bottom.png
-          convert -colorspace gray signal-layer.png old-signal.png
+          convert -colorspace gray ground-layer.png old-ground.png
           convert -colorspace gray power-layer.png old-power.png
           mv ../output/Images/* .
           convert -colorspace gray front-layer.png new-front.png
           convert -colorspace gray bottom-layer.png new-bottom.png
-          convert -colorspace gray signal-layer.png new-signal.png
+          convert -colorspace gray ground-layer.png new-ground.png
           convert -colorspace gray power-layer.png new-power.png
           composite -stereo 0 old-front.png new-front.png diff-front.png
           composite -stereo 0 old-bottom.png new-bottom.png diff-bottom.png
-          composite -stereo 0 old-signal.png new-signal.png diff-signal.png
+          composite -stereo 0 old-ground.png new-ground.png diff-ground.png
           composite -stereo 0 old-power.png new-power.png diff-power.png
           mv PSLab.pdf old-PSLab.pdf
           cp ../docs/schematics/PSLab.pdf .