Update README.md

README.md

@@ -3,6 +3,7 @@
 [![Build Status][1]][2]
 [![codecov][3]][4]
 [![MIT Licence][5]][6]
+[![PkgGoDev](https://pkg.go.dev/badge/github.com/4lie/lookups)](https://pkg.go.dev/github.com/4lie/lookups)
 
 ## Introduction
 
@@ -34,4 +35,4 @@ go get github.com/4lie/lookups
 | <img src="./images/index.png" width="350"/> | How indexing works         |
 | <img src="./images/1.png" width="350"/>     | Simple polygon example     |
 | <img src="./images/2.png" width="350"/>     | Polygon with holes example |
-| <img src="./images/3.png" width="350"/>     | Multiple polygons example  |
+| <img src="./images/3.png" width="350"/>     | Multiple polygons example  |