Update README.md

Author: aafeher

README.md

@@ -1,5 +1,7 @@
 # go-microdata-extract
 
+[![codecov](https://codecov.io/gh/aafeher/go-microdata-extract/graph/badge.svg?token=BD1QYCZESR)](https://codecov.io/gh/aafeher/go-microdata-extract)
+
 A Go package for extracting structured data from HTML.
 
 ## Formats supported
@@ -123,4 +125,4 @@ In this example, structured data is extracted from "https://github.com/aafeher/g
 
 ## Examples
 
-Examples can be found in [/examples](https://github.com/aafeher/go-microdata-extract/tree/main/examples).
+Examples can be found in [/examples](https://github.com/aafeher/go-microdata-extract/tree/main/examples).