doc: update document.

SearchFieldExample/SearchFieldExample.xcodeproj/xcuserdata/wangchujiang.xcuserdatad/xcschemes/xcschememanagement.plist

@@ -7,7 +7,7 @@
 		<key>SearchFieldExample.xcscheme_^#shared#^_</key>
 		<dict>
 			<key>orderHint</key>
-			<integer>1</integer>
+			<integer>0</integer>
 		</dict>
 	</dict>
 </dict>

Sources/SearchField/SearchField.swift

@@ -3,6 +3,24 @@
 
 import SwiftUI
 
+/// The search input box component can be placed in a non-specific location and is consistent with the default search input box style.
+///
+/// ## Example
+///
+/// ```swift
+/// import SearchField
+///
+/// struct ContentView: View {
+///     @State private var searchText = ""
+///     var body: some View {
+///         SearchField(searchText, textFieldChanged: { value in
+///             print("value\(value)")
+///             searchText = value
+///         })
+///     }
+/// }
+/// ```
+/// 
 @available(macOS 10.15, *)
 public struct SearchField: View {
     // A binding to a string value