Document single binary plugins

Signed-off-by: Nolan Brubaker <nolan@heptio.com>

docs/plugins.md

@@ -2,10 +2,12 @@
 
 Heptio Ark has a plugin architecture that allows users to add their own custom functionality to Ark backups & restores 
 without having to modify/recompile the core Ark binary. To add custom functionality, users simply create their own binary 
-containing an implementation of one of Ark's plugin kinds (described below), plus a small amount of boilerplate code to 
-expose the plugin implementation to Ark. This binary is added to a container image that serves as an init container for 
+containing implementations of Ark's plugin kinds (described below), plus a small amount of boilerplate code to 
+expose the plugin implementations to Ark. This binary is added to a container image that serves as an init container for 
 the Ark server pod and copies the binary into a shared emptyDir volume for the Ark server to access. 
 
+Multiple plugins, of any type,  can be implemented in this binary.
+
 A fully-functional [sample plugin repository][1] is provided to serve as a convenient starting point for plugin authors.
 
 ## Plugin Kinds
@@ -17,12 +19,6 @@ Ark currently supports the following kinds of plugins:
 - **Backup Item Action** - executes arbitrary logic for individual items prior to storing them in a backup file
 - **Restore Item Action** - executes arbitrary logic for individual items prior to restoring them into a cluster
 
-## Plugin Naming
-
-Ark relies on a naming convention to identify plugins. Each plugin binary should be named `ark-<plugin-kind>-<name>`,
-where `plugin-kind` is one of `objectstore`, `blockstore`, `backupitemaction`, or `restoreitemaction`, and `name` is
-unique within the plugin kind.
-
 ## Plugin Logging
 
 Ark provides a [logger][2] that can be used by plugins to log structured information to the main Ark server log or 
@@ -32,4 +28,4 @@ within your plugin.
 
 
 [1]: https://github.com/heptio/ark-plugin-example
-[2]: https://github.com/heptio/ark/blob/master/pkg/plugin/logger.go
+[2]: https://github.com/heptio/ark/blob/master/pkg/plugin/logger.go