Implement hook_help()

Created MR , please review.

Thank you.

Patch not working , Hook_help module not found.

Same as #4 after applied the MR! 2 hook_help() not implemented.

@nupurbadola @jaspreet-kaur You need to first install the module then only you'll see the help icon. The provided screenshot is not correct.
Since the module is dependent on three modules which are bundle reference, courier, view bulk operations you need to add those modules first and then install the courier UI module.

The MR looks correct to me and can be merged. We can also add more details about the module. I've commited the changes into the MR. Please review.

Before:

After:

I verified the MR2 on 9.5.8, help() is added. Added screenshots for reference, RTBC++.