I can not replicate this, the "Keep in Dock" option is present in the right lick menu.
As an officially supported alternative to editing .desktop files or using the "Keep in dock" option, you can drag and drop directly form Slingshot to "keep" app launchers in Plank.
I can not replicate this, the "Keep in Dock" option is present in the right lick menu.
As an officially supported alternative to editing .desktop files or using the "Keep in dock" option, you can drag and drop directly form Slingshot to "keep" app launchers in Plank.