Make merge to master clearer in release of top level projects for WEX

[Cruikshanks]

The current solution release process does specify the command to use when generating a new release git merge develop however some users (namely me!) might be tempted to use git merge --no-ff develop assuming its just a typo.

It needs to include some text covering why not to do this, specifically it creates an extra commit which is not on develop, which means they are not exactly in sync when they should be. This makes tracking the history and ensuring the branches are the same easier.