Fix update_all API doc [ci-skip]
Fix update_all API doc [ci-skip]

Multi-line list items must be indented, and inline code must be quoted
using `+` or `<tt>`.  (RDoc does not support backticks.)

MSP-Greg/rails,yawboakye/rails,esparta/rails,yawboakye/rails,rails/rails,georgeclaghorn/rails,yawboakye/rails,MSP-Greg/rails,BlakeWilliams/rails,MSP-Greg/rails,georgeclaghorn/rails,BlakeWilliams/rails,esparta/rails,esparta/rails,yahonda/rails,yahonda/rails,rails/rails,Erol/rails,rails/rails,Erol/rails,MSP-Greg/rails,yahonda/rails,BlakeWilliams/rails,esparta/rails,georgeclaghorn/rails,BlakeWilliams/rails,Erol/rails,rails/rails,Erol/rails,yahonda/rails,georgeclaghorn/rails,yawboakye/rails