Fix triple-click-to-select for IRB code examples [ci-skip]
Fix triple-click-to-select for IRB code examples [ci-skip]

Previously, both the IRB prompt and the line of code were selected on
triple-click.  This commit causes only the line of code to be selected.

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