Include docs for new config entry

Signed-off-by: Luis Mastrangelo <[email protected]>

Author: acuarica

docs/configuration.md

@@ -89,6 +89,7 @@ Unless you need to set a non-default value, it is recommended to only populate o
 | `OPCODELOGGER_ENABLED`                      | "true"                                | Whether the `opcodeLogger` tracer is enabled for a call to `debug_traceTransaction`. This setting should match the value `hiero.mirror.web3.opcode.tracer.enabled` in the Mirror Node used. See [HIP-801](https://hips.hedera.com/hip/hip-801) for more information.                                                                                                                                                                                                                       |
 | `JUMBO_TX_ENABLED`                          | "true"                                | Controls how large transactions are handled during `eth_sendRawTransaction`. When set to `true`, transactions up to 128KB can be sent directly to consensus nodes without using Hedera File Service (HFS), as long as contract bytecode doesn't exceed 24KB. When set to `false`, all transactions containing contract deployments use the traditional HFS approach. This feature leverages the increased transaction size limit to simplify processing of standard Ethereum transactions. |
 | `IP_RATE_LIMIT_STORE`                       | null                                  | Specifies the rate limit store to use for IP-based rate limiting: valid values are "LRU", "REDIS", with the possibility to be extended with a custom implementation (see [Store Selection](rate-limiting.md#store-selection)). If unset, falls back to Redis when `REDIS_ENABLED=true`, otherwise uses in-memory LRU.                                                                                                                                                                      |
+| `READ_ONLY`                                 | "false"                               | Starts the JSON-RPC Relay in Read-Only mode. In Read-Only mode, write operations, _e.g._, `eth_sendRawTransaction` or query operations to the Consensus Node will trigger an `Unsupported operation` error.                                                                                                                                                                                                                                                                                |
 | `REDIS_ENABLED`                             | "true"                                | Enable usage of Redis as shared cache                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
 | `REDIS_RECONNECT_DELAY_MS`                  | "1000"                                | Sets the delay between reconnect retries from the Redis client in ms                                                                                                                                                                                                                                                                                                                                                                                                                       |
 | `REDIS_URL`                                 | "redis://127.0.0.1:6379"              | Sets the url for the Redis shared cache                                                                                                                                                                                                                                                                                                                                                                                                                                                    |