Fix typo in `target_cache_memory_usage` docs (#17825)

changelog.d/17825.doc

+Fix typo in `target_cache_memory_usage` docs.
\ No newline at end of file

docs/usage/configuration/config_documentation.md

@@ -1434,7 +1434,7 @@ number of entries that can be stored.
    Please see the [Config Conventions](#config-conventions) for information on how to specify memory size and cache expiry
    durations.
      * `max_cache_memory_usage` sets a ceiling on how much memory the cache can use before caches begin to be continuously evicted.
-        They will continue to be evicted until the memory usage drops below the `target_memory_usage`, set in
+        They will continue to be evicted until the memory usage drops below the `target_cache_memory_usage`, set in
         the setting below, or until the `min_cache_ttl` is hit. There is no default value for this option.
      * `target_cache_memory_usage` sets a rough target for the desired memory usage of the caches. There is no default value
         for this option.