🎨 update installation

postgres/README.md

@@ -4,6 +4,7 @@ A Postgres storage driver using [lib/pq](https://github.com/lib/pq).
 
 ### Table of Contents
 - [Signatures](#signatures)
+- [Installation](#installation)
 - [Examples](#examples)
 - [Config](#config)
 - [Default Config](#default-config)
@@ -19,6 +20,15 @@ func (s *Storage) Set(key string, val []byte, exp time.Duration) error
 func (s *Storage) Delete(key string) error
 func (s *Storage) Clear() error
 ```
+### Installation
+Postgres is tested on the 2 last [Go versions](https://golang.org/dl/) with support for modules. So make sure to initialize one first if you didn't do that yet:
+```bash
+go mod init github.com/<user>/<repo>
+```
+And then install the postgres implementation:
+```bash
+go get github.com/gofiber/storage/postgres
+```
 
 ### Examples
 Import the storage package.