Clarify one-liner syntax cannot be used with block matchers
Created by: mrageh
Users sometimes try to use the one-liner syntax with block matchers, which can cause RSpec to behave in strange ways. This behaviour is not supported in RSpec because the complexity of implementing it would greatly outweigh the benefits.
This commit just clarifies in the documentation that the one-liner syntax does not support block matchers.
Possible fix for https://github.com/rspec/rspec-expectations/issues/805