Define rclone's remote where it is first used

The documents use "remote key" for something else, so "remote" as
rclone's noun is now defined on first use: a remote is a storage service
set up in rclone. Changed in `README.md` (the destination bullet),
`docs/REPOSTRUCTURE.md` (the opening) and `config.example.yml` (the
`storage_url` comment).

Model: fable-5-1

README.md

@@ -36,7 +36,8 @@ It was written to meet these requirements together:
 - Small files are packed together into large objects. This keeps the number of
   S3 requests low.
 - File contents, names, paths and metadata are encrypted at the destination.
-- Three kinds of destination: S3, a local directory and any rclone remote.
+- Three kinds of destination: S3, a local directory and any rclone remote. A
+  remote is a storage service set up in rclone.
 - Regular files, symlinks and directories are backed up, with their permissions,
   owners and modification times.
 - Pure Go, with no C code. It builds for Linux and macOS on `amd64` and `arm64`.

config.example.yml

@@ -278,8 +278,8 @@ exclude:
 # An s3:// URL also needs s3.access_key_id and s3.secret_access_key below
 # A file:// path must be absolute, and the directory must already exist:
 # vaultik never creates it
-# An rclone:// URL names a remote of rclone (https://rclone.org/); the remote
+# An rclone:// URL names an rclone remote (https://rclone.org/), a storage
-# must be defined in rclone's own config (rclone config)
+# service set up in rclone's own config (rclone config)
 storage_url: "rclone://myremote/path/to/backups"
 
 # S3-compatible storage configuration

docs/REPOSTRUCTURE.md

@@ -4,8 +4,8 @@ This document describes what `vaultik` stores at the destination. It covers the
 layout, what the layout protects, and the risks it accepts.
 
 The destination is the place the backups are stored. It is an S3 bucket and
-prefix, a local directory or a remote of [rclone](https://rclone.org/). The
+prefix, a local directory or an [rclone](https://rclone.org/) remote. A remote
-layout is the same on all three.
+is a storage service set up in rclone. The layout is the same on all three.
 
 ## Terms