feat(rclone): create completion plugin (#12754)

plugins/rclone/README.md

@@ -0,0 +1,9 @@
+# Rclone plugin
+
+This plugin adds completion for [Rclone](https://rclone.org/), the command-line program to manage files on cloud storage.
+
+To use it, add `rclone` to the plugins array in your zshrc file:
+
+```zsh
+plugins=(... rclone)
+```