Update plugin owned capabilities documentation

Mention in first sentence that capabilities can be also used with
UiActions. Also fixes small copy-paste error from UiActions section.

Change-Id: I686e7b40f04216367751b8829295973fa6fa2c09
Signed-off-by: Dariusz Luksza <dariusz@luksza.org>
diff --git a/Documentation/dev-plugins.txt b/Documentation/dev-plugins.txt
index d89f79e..39cd1fc 100644
--- a/Documentation/dev-plugins.txt
+++ b/Documentation/dev-plugins.txt
@@ -853,7 +853,7 @@
 == Plugin Owned Capabilities
 
 Plugins may provide their own capabilities and restrict usage of SSH
-commands to the users who are granted those capabilities.
+commands or `UiAction` to the users who are granted those capabilities.
 
 Plugins define the capabilities by overriding the `CapabilityDefinition`
 abstract class:
@@ -868,7 +868,7 @@
 }
 ----
 
-If no Guice modules are declared in the manifest, UI actions may
+If no Guice modules are declared in the manifest, capability may
 use auto-registration by providing an `@Export` annotation:
 
 [source,java]