Adding query docs
Query spelling updates
Fixeds pre blake
Changing results set to result set
Added missing backticks.
Corrected description of sortDescriptors taking array.
Change casing of log statement for consistency with error log statement.
Removed * from NSUInteger for count.
Replaced predicate abbreviations.
Changed name of Layer client property for consistency.
Removed * from NSUInteger for count.
Removed extra space for array.
Added missing period to end of bullet point for consistency.
Fixed typo of its.
Removed extra space in creating query controller.
Removed setting error to nil for consistency.
Reworded phrase.
Rephrased wording about observing notification.
Removed 'The' when talking about a class.
Reworded explanation of query controller observation.