* add 'aria-label' into some elements without the label
* add 'aris-label' into some visual elements
* replace some 'a' elements have a button action to 'button'
no functional change here, but familiar Rails users will see view files in the
locations they expect. this also slightly simplifies controller code
there is one attendant change in the wiki at `rails_3/A1-SQL-Injection-Interpolation.md`
that I'm happy to make after the PR is merged.