Add Linode docker volume plugin

Signed-off-by: Zhiwei Liang <zliang@akamai.com>

Author: zliang-akamai

docs/extend/legacy_plugins.md

@@ -74,6 +74,7 @@ The sections below provide an inexhaustive overview of available plugins.
 | [Infinit volume plugin](https://infinit.sh/documentation/docker/volume-plugin)                     | A volume plugin that makes it easy to mount and manage Infinit volumes using Docker.                                                                                                                                                                                                                          |
 | [IPFS Volume Plugin](https://github.com/vdemeester/docker-volume-ipfs)                              | An open source volume plugin that allows using an [ipfs](https://ipfs.io/) filesystem as a volume.                                                                                                                                                                                                            |
 | [Keywhiz plugin](https://github.com/calavera/docker-volume-keywhiz)                                | A plugin that provides credentials and secret management using Keywhiz as a central repository.                                                                                                                                                                                                               |
+| [Linode Volume Plugin](https://github.com/linode/docker-volume-linode)                             | A plugin that adds the ability to manage Linode Block Storage as Docker Volumes from within a Linode.                                                                                                                                                                                                    |
 | [Local Persist Plugin](https://github.com/CWSpear/local-persist)                                   | A volume plugin that extends the default `local` driver's functionality by allowing you specify a mountpoint anywhere on the host, which enables the files to *always persist*, even if the volume is removed via `docker volume rm`.                                                                         |
 | [NetApp Plugin](https://github.com/NetApp/netappdvp) (nDVP)                                        | A volume plugin that provides direct integration with the Docker ecosystem for the NetApp storage portfolio. The nDVP package supports the provisioning and management of storage resources from the storage platform to Docker hosts, with a robust framework for adding additional platforms in the future. |
 | [Netshare plugin](https://github.com/ContainX/docker-volume-netshare)                              | A volume plugin that provides volume management for NFS 3/4, AWS EFS and CIFS file systems.                                                                                                                                                                                                                   |