update README

README.md

@@ -1,10 +1,19 @@
-Xciel is a Xcode Extension influented by ci (di) command in Vim.
-This command can delete, select and comment-out the region which the cursor is.
-For example, see the following gif.
+Xciel is a Xcode Extension influenced by "ci" ("di") command in Vim.  
 
-# The behavior
+This command deletes, selects and comment-out the region (scope) where enclosed in brackets. 
+
+Unlike the "ci" command in Vim, the region is defined by the cursor position.  
+
+# Introduction
+
+Xciel commands are slightly similar to "ci" command in Vim, but these commands search the region by current cursor position.  
+
+It automatically searches the parent brackets ("(){}[]") and executes a command.
+
+## Delete
+
+Xciel Delete command behave like the following.  
 
-As a introduction, the Delete command behave like the following.
 (the cursor position is expressed as $)
 
 1. 
@@ -23,7 +32,8 @@ if x.isEasy {
 }
 ```
 
-As you can see, the cursor's scope is inside of the `do(what: @x)` and it deletes `what: x`.
+As you can see, the cursor's scope is inside of the `do(what: @x)` and it deletes `what: x`.  
+
 By the way, if the cursor is outside of the `do()`, then
 
 1.
@@ -44,11 +54,37 @@ if !(x.isEasy) {
 
 Now, you can imagine the Delete command's behavior.
 
+## Select
+
+Select command simply selects the scope.
+
+## Comment
+
+Comment out command toggles lines in the scope.
+
 NOTE: Comment out command can toggle comments in the region!
 
+## Greedy
+
+Each commends has greedy option.
+
+These commands are usefull in specific situation.  
+
+### Select
+
+This command selects the region where exntended to the first column of the start line and the last column of the end line.
+
+### Delete
+
+This command deletes the region as same as the Select command select.
+
+### Comment out 
+
+This command comments the region as same sa the Select command select.
+
 # Installation
 
-Download from the release page and open Xciel.
+Download from the release page and open Xciel.app.
 
 Then, open System Preferences > Extensions and enable Xciel Extension.
 
@@ -58,4 +94,4 @@ If you cannot find Xcode Menu > Editor > Xciel Extension, please reopen Xcode.
 
 Select Xcode Menu > Editor > Xciel Extensions.
 
-However, I highly recommend setting keybind to the Xciel commands.
+I highly recommend setting keybind to the Xciel commands though :)