Clarify use of rescue_from [ci skip]
Clarify use of rescue_from [ci skip]

`rescue_from` works for rescuing exceptions in controller actions, but it's not specific to ActionController.

This change updates the docs to clarify the specifics of how `rescue_from` is used and that its use goes beyond controller actions.

Note: I believe the original addition of this documentation was added as part of the move from [`ActionController::Rescue` to `ActiveSupport::Rescuable`](https://github.com/rails/rails/commit/259a7a844b53b7d508145cc61fed9e11581e5409#diff-2276a3674b84e1262c94cc36346f9fbd8d00e0a4542bb991a8846c06d86335b1R12)

Stellenticket/rails,Stellenticket/rails,BlakeWilliams/rails,joonyou/rails,kddeisz/rails,kddeisz/rails,yahonda/rails,georgeclaghorn/rails,rails/rails,kmcphillips/rails,Edouard-chin/rails,tjschuck/rails,yawboakye/rails,georgeclaghorn/rails,lcreid/rails,lcreid/rails,Erol/rails,BlakeWilliams/rails,joonyou/rails,BlakeWilliams/rails,tjschuck/rails,Envek/rails,esparta/rails,EmmaB/rails-1,BlakeWilliams/rails,yawboakye/rails,MSP-Greg/rails,Erol/rails,joonyou/rails,betesh/rails,esparta/rails,tgxworld/rails,Stellenticket/rails,Vasfed/rails,MSP-Greg/rails,EmmaB/rails-1,lcreid/rails,yawboakye/rails,rails/rails,Vasfed/rails,Envek/rails,rails/rails,Edouard-chin/rails,kmcphillips/rails,tgxworld/rails,tgxworld/rails,tjschuck/rails,esparta/rails,georgeclaghorn/rails,MSP-Greg/rails,betesh/rails,joonyou/rails,Erol/rails,Vasfed/rails,betesh/rails,Erol/rails,bogdanvlviv/rails,yahonda/rails,kddeisz/rails,Envek/rails,kmcphillips/rails,Vasfed/rails,esparta/rails,EmmaB/rails-1,tgxworld/rails,yahonda/rails,MSP-Greg/rails,Envek/rails,rails/rails,bogdanvlviv/rails,lcreid/rails,georgeclaghorn/rails,tjschuck/rails,Edouard-chin/rails,betesh/rails,Edouard-chin/rails,yahonda/rails,kddeisz/rails,Stellenticket/rails,kmcphillips/rails,yawboakye/rails,bogdanvlviv/rails,bogdanvlviv/rails