Add FastCache to the Projects using this package
Add FastCache to the Projects using this package

Add [FastCache](https://github.com/VictoriaMetrics/fastcache) to the Projects using this package on README.md.

Source: https://github.com/VictoriaMetrics/fastcache/blob/8835719dc76cc26f97026e3aa726742e7d2f1053/fastcache.go#L11
cespare/xxhash