Use generic icon if unavailable (#48)

* Delete gear.png

* Add no-icon.png

* Update icons-dumb.yml

* Add files via upload

* Add files via upload

* Add files via upload

* Add files via upload

Author: ivan-hc

.github/workflows/icons-dumb.yml

@@ -28,7 +28,7 @@ jobs:
           MDS=$(ls apps/* | sed 's:.*/::; s/.md$//g')
           for m in $MDS; do
           	if ! test -f icons/"$m".png; then
-          		cp -r gear.png "icons/$m.png"
+          		cp -r no-icon.png "icons/$m.png"
           	fi
           done
           rm -f icons/*.md