Update readme

Author: vmihailenco

.github/FUNDING.yml

@@ -0,0 +1 @@
+custom: ['https://uptrace.dev']

README.md

@@ -11,19 +11,18 @@ feature.
 
 ## Installation
 
-redis_rate requires a Go version with [Modules](https://github.com/golang/go/wiki/Modules) support
-and uses import versioning. So please make sure to initialize a Go module before installing
-redis_rate:
+redis_rate supports 2 last Go versions and requires a Go version with
+[modules](https://github.com/golang/go/wiki/Modules) support. So make sure to initialize a Go
+module:
 
 ```shell
 go mod init github.com/my/repo
-go get github.com/go-redis/redis_rate/v8
 ```
 
-Import:
+And then install redis*rate/v9 (note \_v9* in the import; omitting it is a popular mistake):
 
-```go
-import "github.com/go-redis/redis_rate/v8"
+```shell
+go get github.com/go-redis/redis_rate/v9
 ```
 
 ## Example