add gin user - photoprism (#1601)

README.md

@@ -1964,3 +1964,4 @@ Awesome project lists using [Gin](https://github.com/gin-gonic/gin) web framewor
 * [drone](https://github.com/drone/drone): Drone is a Continuous Delivery platform built on Docker, written in Go.
 * [gorush](https://github.com/appleboy/gorush): A push notification server written in Go.
 * [fnproject](https://github.com/fnproject/fn): The container native, cloud agnostic serverless platform.
+* [photoprism](https://github.com/photoprism/photoprism): Personal photo management powered by Go and Google TensorFlow.