Add guidance for safe navigation operator (&.)

[andyw8]

Reading https://thoughtbot.com/blog/ruby-safe-navigation reminded me that over-use of &. is common. I think it would be helpful to add a guideline such as:

Avoid long chains of &.. Replace with . if they introduce unnecessary conditional logic. Consider other approaches such as delegation.

This could also be added as a rule in RuboCop with a maximum number of chained calls (e.g. 2 or 3).

[bbatsov]

Yeah, I agree. We should definitely add some guidelines about &..

[Gauravpurohit409]

Created PR for it please review it #912

[pirj]

Fixed in #912