update README.md

Author: p-x9

README.md

@@ -2,6 +2,11 @@
 
 SwiftPackage Plugin for executing arbitrary ShellScript.
 
+## Feature
+- BuildToolPlugin: RunScriptPlugin
+- CommandPlugin: RunScriptCommandPlugin
+- XcodeBuildToolPlugin: RunScriptPlugin
+- XcodeCommandPlugin: RunScriptCommandPlugin
 
 ## Usage
 Place the file named `runscript.yml`(or `.runscript.yml`) in the root of the project.
@@ -35,6 +40,10 @@ build: # build Command
    - name: "Hello"
      script: "echo Hello"
 
+command: # Command Plugin
+  - name: "Hello from Command"
+    script: "echo 'Hello from Command'"
+
 all: # run in `prebuild`, `build`...
    - name: "Hello(all)"
      script: "echo Hello(all)"