docs(`anvil`) `--transaction-block-keeper` flag is not documented

[sabotagebeats]

Component

Anvil

Describe the feature you would like

there is a memory leak in anvil. it causes my anvil node to fail in docker. I am trying to reduce memory usage.

the --transaction-block-keeper switch does not seem to be documented so I am not sure what it is doing exactly.

Additional context

https://github.com/foundry-rs/foundry/issues/3478