Nx command should provide steps to upgrade Nx globally when needed

[jvskriubakken]

When you execute nx --version and Local and Global version differs,
then Nx should give you command you can run to upgrade your Global version to the same as Local.

Nx has information about OS and packager manager and should be able to provide appropriate steps, like specified in the docs.

This would help in removing a pain point from those developers that are not Nx experts but still have to deal with it.
@juristr