Add type to node-redis cluster function

Should have been part of #208

Author: nfriedly

readme.md

@@ -140,7 +140,7 @@ below:
 | Library                                                            | Function                                                                      |
 | ------------------------------------------------------------------ | ----------------------------------------------------------------------------- |
 | [`node-redis`](https://github.com/redis/node-redis)                | `async (...args: string[]) => client.sendCommand(args)`                       |
-| [`node-redis`](https://github.com/redis/node-redis) (cluster)      | `async (...args) => cluster.sendCommand(args[1], false, args)`                |
+| [`node-redis`](https://github.com/redis/node-redis) (cluster)      | `async (...args: string[]) => cluster.sendCommand(args[1], false, args)`                |
 | [`ioredis`](https://github.com/luin/ioredis)                       | `async (command: string, ...args: string[]) => client.call(command, ...args)` |
 | [`handy-redis`](https://github.com/mmkal/handy-redis)              | `async (...args: string[]) => client.nodeRedis.sendCommand(args)`             |
 | [`tedis`](https://github.com/silkjs/tedis)                         | `async (...args: string[]) => client.command(...args)`                        |