Add imcache (#4847)

README.md

@@ -645,6 +645,7 @@ _Data stores with expiring records, in-memory distributed data stores, or in-mem
 - [go-mcache](https://github.com/OrlovEvgeny/go-mcache) - Fast in-memory key:value store/cache library. Pointer caches.
 - [gocache](https://github.com/eko/gocache) - A complete Go cache library with multiple stores (memory, memcache, redis, ...), chainable, loadable, metrics cache and more.
 - [groupcache](https://github.com/golang/groupcache) - Groupcache is a caching and cache-filling library, intended as a replacement for memcached in many cases.
+- [imcache](https://github.com/erni27/imcache) - A generic in-memory cache Go library. It supports expiration, sliding expiration, max entries limit, eviction callbacks and sharding.
 - [remember-go](https://github.com/rocketlaunchr/remember-go) - A universal interface for caching slow database queries (backed by redis, memcached, ristretto, or in-memory).
 - [theine](https://github.com/Yiling-J/theine-go) - High performance, near optimal in-memory cache with proactive TTL expiration and generics.
 - [timedmap](https://github.com/zekroTJA/timedmap) - Map with expiring key-value pairs.