fix: revert docstring change for params field

The params docstring is user-facing and should remain generic,
linking to the docs for details. It shouldn't call out specific
params or reference spec items.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

specifications/api-docstrings.md

@@ -329,7 +329,7 @@ Enables messages to be published and subscribed to. Also enables historic messag
 | properties: ChannelProperties ||| CP1, RTL15 | A [`ChannelProperties`]{@link ChannelProperties} object. |
 | push: PushChannel |||| A [`PushChannel`]{@link PushChannel} object. |
 | modes: readonly [ChannelMode] ||| RTL4m | An array of [`ChannelMode`]{@link ChannelMode} objects. |
-| params: readonly `Dict<String, String>` ||| RTL4k1 | Optional [channel parameters](https://ably.com/docs/realtime/channels/channel-parameters/overview) that configure the behavior of the channel. The `echo` channel param can be set to `"false"` to suppress messages originating from this connection being echoed back on this channel, regardless of the connection-level `echoMessages` setting. See RTL4n. |
+| params: readonly `Dict<String, String>` ||| RTL4k1 | Optional [channel parameters](https://ably.com/docs/realtime/channels/channel-parameters/overview) that configure the behavior of the channel. |
 | attach() => io ||| RTL4d | Attach to this channel ensuring the channel is created in the Ably system and all messages published on the channel are received by any channel listeners registered using [`subscribe()`]{@link RealtimeChannel#subscribe}. Any resulting channel state change will be emitted to any listeners registered using the [`on()`]{@link EventEmitter#on} or [`once()`]{@link EventEmitter#once} methods. A callback may optionally be passed in to this call to be notified of success or failure of the operation. As a convenience, `attach()` is called implicitly if [`subscribe()`]{@link RealtimeChannel#subscribe} is called on the channel or [`subscribe()`]{@link RealtimePresence#subscribe} is called on the [`RealtimePresence`]{@link RealtimePresence} object for this channel, unless you’ve set the [`attachOnSubscribe`]{@link ChannelOptions#attachOnSubscribe} channel option to `false`. It is also called implicitly if [`enter()`]{@link RealtimePresence#enter} is called on the [`RealtimePresence`]{@link RealtimePresence} object for this channel.
 | detach() => io ||| RTL5e | Detach from this channel. Any resulting channel state change is emitted to any listeners registered using the [`on()`]{@link EventEmitter#on} or [`once()`]{@link EventEmitter#once} methods. A callback may optionally be passed in to this call to be notified of success or failure of the operation. Once all clients globally have detached from the channel, the channel will be released in the Ably service within two minutes. |
 | history(start: Time, end: Time api-default now(), direction: .Backwards \| .Forwards api-default .Backwards, limit: int api-default 100, untilAttach: Bool default false) => io `PaginatedResult<Message>` ||| RSL2a | Retrieves a [`PaginatedResult`]{@link PaginatedResult} object, containing an array of historical [`Message`]{@link Message} objects for the channel. If the channel is configured to persist messages, then messages can be retrieved from history for up to 72 hours in the past. If not, messages can only be retrieved from history for up to two minutes in the past. |