Modify unscoped usage guide to include chaining [ci skip]

[jeffminnear]

No description provided.

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[eileencodes]

Hi @jeffminnear thanks for the PR! Here are a couple of changes I think would make this better:

1. Add the SQL for the examples you added
2. Put the note about how unscoped and scope don't work together so you need to use a block. The change you made doesn't make it clear that you use a block when you need to scope and unscope.
3. Add [ci skip] to your commit message (for guides and documentation PR's) so that travis doesn't run.

Thanks!

[jeffminnear]

2. Put the note about how unscoped and scope don't work together so you need to use a block. The change you made doesn't make it clear that you use a block when you need to scope and unscope.

It actually seems that they do work together now. I have tested it in the Rails console written as both a scope and a class method, and it appears to be working fine.

[eliotsykes]

Confirmed unscoped chained with a named scope working, e.g.

# Seen working
Subscription.expired.unscoped
Subscription.unscoped.expired

[eileencodes]

Ok, thanks for checking the scoping! Can you squash your commits into one?