README.md: Add goimghdr

README.md

@@ -816,6 +816,7 @@ See [go-hardware](https://github.com/rakyll/go-hardware) for a comprehensive lis
 * [go-webcolors](https://github.com/jyotiska/go-webcolors) - Port of webcolors library from Python to Go.
 * [gocv](https://github.com/hybridgroup/gocv) - Go package for computer vision using OpenCV 3.3+.
 * [goimagehash](https://github.com/corona10/goimagehash) - Go Perceptual image hashing package.
+* [goimghdr](https://github.com/corona10/goimghdr) - The imghdr module determines the type of image contained in a file for go
 * [govatar](https://github.com/o1egl/govatar) - Library and CMD tool for generating funny avatars.
 * [image2ascii](https://github.com/qeesung/image2ascii) - Convert image to ASCII.
 * [imagick](https://github.com/gographics/imagick) - Go binding to ImageMagick's MagickWand C API.