doc: use "repository" in guides versus repo

Fix remaining instances in the guides where we
use repo instead of repository.

Signed-off-by: Michael Dawson <mdawson@devrus.com>

PR-URL: https://github.com/nodejs/node/pull/39198


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Harshitha K P <harshitha014@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>