docs: Update target name in documentation target README

Author: euanh

Package.swift

@@ -78,9 +78,7 @@ let package = Package(
             ),
             dependencies: [.target(name: "containertool")]
         ),
-        // Empty target that builds the DocC catalog at /SwiftContainerPluginDocumentation/Documentation.docc.
-        // The ContainerImageBuilder catalog includes high-level, user-facing documentation about using
-        // the ContainerImageBuilder plugin from the command-line.
+        // Empty target which builds high-level, user-facing documentation about using the plugin from the command-line.
         .target(
             name: "swift-container-plugin",
             exclude: ["README.md"]

Sources/swift-container-plugin/README.md

@@ -1,7 +1,6 @@
-# ContainerImageBuilder Plugin Documentation
+# Swift Container Plugin User Documentation
 
-`ContainerImageBuilderPluginDocumentation` is an otherwise empty target that includes high-level,
-user-facing documentation about using the ContainerImageBuilder plugin from the command-line.
+This is an otherwise empty target that includes high-level, user-facing documentation about using the plugin from the command-line.
 
 To preview the documentation, run the following command: