[New Feature] git-submodule-move - Easily move submodules

I've recently had need to re-arrange more than ten submodules within a project and discovered there is apparently no easy way to do it.

Using some suggestions I found on Stack Overflow I eventually figured out the steps required. Because the steps can be complex I thought it would be handy to have a tool to automate the functionality.

I have put together a reasonably bullet-proof shell script "git-submodule-move" that does the job pretty well. I've put it through quite a bit of testing and trusted it with my own project and it has performed well.

I've published to github so others can use and improve it.

https://github.com/iam-TJ/git-submodule-move