update readme with playground

README.md

@@ -9,15 +9,19 @@ This library takes a literal codepoint string and calculates the UTF-8 encoding
 ```go
 package main
 
-import "github.com/RageCage64/go-utf8-codepoint-converter/codepoint"
+import (
+	"fmt"
+
+	"github.com/RageCage64/go-utf8-codepoint-converter/codepoint"
+)
 
 func main() {
-    codepointStr := "U+1F60A"
-    utf8bytes, _ := codepoint.Convert(codepointStr)
-    fmt.Println(string(utf8bytes))
-    codepointStr := "\\U0001F603"
-    utf8bytes, _ = codepoint.Convert(codepointStr)
-    fmt.Println(string(utf8bytes))
+	codepointStr := "U+1F60A"
+	utf8bytes, _ := codepoint.Convert(codepointStr)
+	fmt.Println(string(utf8bytes))
+	codepointStr = "\\U0001F603"
+	utf8bytes, _ = codepoint.Convert(codepointStr)
+	fmt.Println(string(utf8bytes))
 }
 ```
 Result:
@@ -25,3 +29,4 @@ Result:
 😊
 😃
 ```
+Playground: https://go.dev/play/p/Nd6xxU3k7QI