As far as I know, you can’t get an executable script like that to act like an app that’s launchable when double clicked from Finder or clicked the Dock. Even though it’s executable.
You can create a folder with a '.app' extension and put the script in there. Just make sure the script is executable with chmod and remove the '.sh' extension.
I just tried it, seems to work! Make your script with custom options, mark it as executable, make an alias for it within finder, and drag that into your dock.