wish: document differences between "npm shrinkwrap" and "npm-shrinkwrap"

[markstos]

It would be helpful if the docs contained a section to summarize the differences between "npm-shrinkwrap" and "npm shrinkwrap".

[markstos]

Confusingly, if you run man npm-shrinkwrap you'll get the docs for npm shrinkwrap, which makes it appear that the commands are the same, but npm-shrinkwrap --help documents options like sync which npm shrinkwrap does not have.

[Raynos]

The README has a motivation section documenting the things that npm-shrinkwrap works around.

[MattiSG]

And documenting the rationale for making this an external package rather than an NPM contribution would be interesting too ;)

[markstos]

Our experience has been that after upgrading to npm 3, we no longer needed npm-shrinkwrap and quit using it. npm shrinkwrap works well enough and supported is integrated into npm install, so commands like npm install --save also update the shrinkwrap file.