[BUG] `LINDEX` method has invalid signature

**Describe the bug**

`LINDEX` method has invalid signature, `(key: string, element: string): Array<string>` instead of  `(key: string, index: number): string`, in the file [LINDEX.ts](https://github.com/redis/node-redis/blob/master/packages/client/lib/commands/LINDEX.ts)