Add `:nodoc` to `ActiveModel::Errors`
Add `:nodoc` to `ActiveModel::Errors`

Three classes in `active_model/errors` look internal only.

Edouard-chin/rails,MSP-Greg/rails,esparta/rails,lcreid/rails,joonyou/rails,kddeisz/rails,Edouard-chin/rails,Envek/rails,yahonda/rails,joonyou/rails,kddeisz/rails,Stellenticket/rails,joonyou/rails,Erol/rails,Vasfed/rails,kmcphillips/rails,yahonda/rails,yahonda/rails,Edouard-chin/rails,Vasfed/rails,Envek/rails,MSP-Greg/rails,kmcphillips/rails,georgeclaghorn/rails,esparta/rails,rails/rails,BlakeWilliams/rails,esparta/rails,lcreid/rails,BlakeWilliams/rails,kddeisz/rails,georgeclaghorn/rails,georgeclaghorn/rails,rails/rails,georgeclaghorn/rails,BlakeWilliams/rails,yawboakye/rails,Vasfed/rails,BlakeWilliams/rails,Erol/rails,MSP-Greg/rails,Stellenticket/rails,Edouard-chin/rails,yawboakye/rails,Erol/rails,joonyou/rails,kddeisz/rails,yawboakye/rails,esparta/rails,rails/rails,lcreid/rails,Stellenticket/rails,Envek/rails,Envek/rails,lcreid/rails,Stellenticket/rails,kmcphillips/rails,rails/rails,Vasfed/rails,yahonda/rails,Erol/rails,yawboakye/rails,kmcphillips/rails,MSP-Greg/rails