update readme.md

Author: rlarjsdn3

.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata

@@ -1,4 +1,4 @@
-Copyright (c) 2025 rlarjsdn3 <rlarjsdn3@naver.com>
+Copyright (c) 2025 SOWOL-KIM <rlarjsdn3@naver.com>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

LICENSE

@@ -0,0 +1,21 @@
+// swift-tools-version: 5.5
+import PackageDescription
+
+let package = Package(
+    name: "StringExtension",
+    platforms: [
+        .iOS(.v15)
+    ],
+    products: [
+        .library(
+            name: "StringExtension",
+            targets: ["StringExtension"]
+        )
+    ],
+    targets: [
+        .target(
+            name: "StringExtension",
+            path: "StringExtension/Classes"
+        )
+    ]
+)

Package.swift

@@ -1,29 +1,46 @@
-# StringExtension
+# String-Extension
 
-[![CI Status](https://img.shields.io/travis/rlarjsdn3/StringExtension.svg?style=flat)](https://travis-ci.org/rlarjsdn3/StringExtension)
+[![SwiftPM](https://img.shields.io/badge/SPM-supported-DE5C43.svg?style=flat)](https://swift.org/package-manager/)
 [![Version](https://img.shields.io/cocoapods/v/StringExtension.svg?style=flat)](https://cocoapods.org/pods/StringExtension)
 [![License](https://img.shields.io/cocoapods/l/StringExtension.svg?style=flat)](https://cocoapods.org/pods/StringExtension)
 [![Platform](https://img.shields.io/cocoapods/p/StringExtension.svg?style=flat)](https://cocoapods.org/pods/StringExtension)
 
-## Example
+## Usage
 
-To run the example project, clone the repo, and run `pod install` from the Example directory first.
+If you want to find a specific character in a string, you can code it as shown below:
 
-## Requirements
+```swift
+let text = "John Appleseed"
+```
+
+```swift
+text[3]             // Returns the Character "h"
+text[safe: 9]       // Returns the Optional Character "l"
+text[safe: 100]     // Returns the nil
+```
 
 ## Installation
 
-StringExtension is available through [CocoaPods](https://cocoapods.org). To install
-it, simply add the following line to your Podfile:
+### Swift Package Manager 
+
+You can use The Swift Package Manager to install PTString-Subscript by addint the description to your Package.swift file:
+
+```swift
+dependencies: [
+    .package(url: "https://github.com/rlarjsdn3/String-Extension-Swift", from: "0.1.0")
+]
+```
+
+### CocoaPods
 
 ```ruby
-pod 'StringExtension'
+pod "SwiftExtension"
 ```
 
 ## Author
 
-rlarjsdn3, rlarjsdn3@naver.com
+SOWOL-KIM, rlarjsdn3@naver.com
 
 ## License
 
-StringExtension is available under the MIT license. See the LICENSE file for more info.
+PTStringSubscript is available under the MIT license. See the LICENSE file for more info.