The read builtin command has -e option
-e Use Readline to handle input. This permits input editing in the same
manner as the command line.
What's Readline in the specification:
$ man readline
No manual entry for readline
$ man Readline
No manual entry for Readline
There are no details of readline.
type readreveals (and you already found out),readis a shell builtin. Those are documented in the shell's manual pages, soman bashis the correct source in your case. – dessert Apr 14 '18 at 06:52