docs: Fix typo (#1041)

Signed-off-by: hayk96 <hayko5999@gmail.com>

Author: hayk96

README.md

@@ -171,7 +171,7 @@ scrape_configs:
 | redis.user                          | REDIS_USER                                       | User name to use for authentication (Redis ACL for Redis 6.0 and newer).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
 | redis.password                      | REDIS_PASSWORD                                   | Password of the Redis instance, defaults to `""` (no password).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
 | redis.password-file                 | REDIS_PASSWORD_FILE                              | Password file of the Redis instance to scrape, defaults to `""` (no password file).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
-| check-keys                          | REDIS_EXPORTER_CHECK_KEYS                        | Comma separated list of key patterns to export value and length/size, eg: `db3=user_count` will export key `user_count` from db `3`. db defaults to `0` if omitted. The key patterns specified with this flag will be found using [SCAN](https://valkey.io/commands/scan).  Use this option if you need glob pattern matching; `check-single-keys` is faster for non-pattern keys. Warning: using `--check-keys` to match a very large number of keys can slow down the exporter to the point where it doesn't finish scraping the redis instance. --check-keys doesn't work in fluster mode as "SCAN" does not work across multiple instances. |
+| check-keys                          | REDIS_EXPORTER_CHECK_KEYS                        | Comma separated list of key patterns to export value and length/size, eg: `db3=user_count` will export key `user_count` from db `3`. db defaults to `0` if omitted. The key patterns specified with this flag will be found using [SCAN](https://valkey.io/commands/scan).  Use this option if you need glob pattern matching; `check-single-keys` is faster for non-pattern keys. Warning: using `--check-keys` to match a very large number of keys can slow down the exporter to the point where it doesn't finish scraping the redis instance. --check-keys doesn't work in cluster mode as "SCAN" does not work across multiple instances. |
 | check-single-keys                   | REDIS_EXPORTER_CHECK_SINGLE_KEYS                 | Comma separated list of keys to export value and length/size, eg: `db3=user_count` will export key `user_count` from db `3`. db defaults to `0` if omitted.  The keys specified with this flag will be looked up directly without any glob pattern matching.  Use this option if you don't need glob pattern matching;  it is faster than `check-keys`.                                                                                                                                                                                                                                                                                         |
 | check-streams                       | REDIS_EXPORTER_CHECK_STREAMS                     | Comma separated list of stream-patterns to export info about streams, groups and consumers. Syntax is the same as `check-keys`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
 | check-single-streams                | REDIS_EXPORTER_CHECK_SINGLE_STREAMS              | Comma separated list of streams to export info about streams, groups and consumers. The streams specified with this flag will be looked up directly without any glob pattern matching.  Use this option if you don't need glob pattern matching;  it is faster than `check-streams`.                                                                                                                                                                                                                                                                                                                                                            |