add country code to flag converter

README.md

@@ -19,13 +19,18 @@ go get github.com/enescakir/emoji
     )
 
     func main() {
-        fmt.Printf("hello %v from %v\n", emoji.WavingHand, emoji.FlagsForFlagTurkey)
+        fmt.Printf("hello %v from %v\n", 
+            emoji.WavingHand, 
+            emoji.FlagsForFlagTurkey,
+        )
         fmt.Printf("different skin tones. default: %v light: %v dark: %v\n", 
             emoji.ThumbsUp,
             emoji.OkHand.Tone(emoji.Light),
             emoji.CallMeHand.Tone(emoji.Dark),
         )
-        fmt.Printf("emoji with multiple skins: %v\n", emoji.PeopleHoldingHands.Tone(emoji.Light, emoji.Dark))
+        fmt.Printf("emoji with multiple skins: %v\n", 
+            emoji.PeopleHoldingHands.Tone(emoji.Light, emoji.Dark),
+        )
     }
 
     /* OUTPUT
@@ -40,14 +45,18 @@ go get github.com/enescakir/emoji
 
 This package contains Full Emoji List v12.0 based on [https://unicode.org/Public/emoji/12.0/emoji-test.txt](https://unicode.org/Public/emoji/12.0/emoji-test.txt).
 
+Also, you can generate country flag emoji with [ISO 3166 Alpha2](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2) codes:
+```go
+    emoji.CountryFlag("tr") // 🇹🇷
+```
+
 ## Testing :hammer:
 ``` bash
 go test
 ```
 
 ## Todo :pushpin:
 * Add `godoc`
-* Add country code to flag emoji converter
 * Add badges to README
 * Add tests
 * Add emoji constant generator