Possibly out of date documentation about nrefactor repl

**Describe the bug**
A clear and concise description of what the bug is.

https://github.com/boot-clj/boot/wiki/Cider-REPL
in the first example suggests using `nrefactor-repl`,
however

https://github.com/clojure-emacs/clj-refactor.el/wiki/installation#refactor-nrepl-middleware
says that
`From version 2.2.0 onwards if cider-jack-in is used it is injected automatically.`

I had problems with cider-jack-in and removal of `nrefactor-repl` made possible to start repl in boot namespace.

Review the first example on the Boot Cider-REPL wiki page and compare its nrefactor-repl guidance with the clj-refactor.el installation page linked in the issue. Update the documentation so it reflects the current cider-jack-in behavior, then verify that the example no longer recommends an unnecessary or conflicting setup.

Written by the indexing model from the issue text.