`GET /initialSync`'s response mentions a `limit` parameter which is not documented for the request

**Link to problem area**: https://spec.matrix.org/v1.13/client-server-api/#get_matrixclientv3roomsroomidinitialsync_response-200_paginationchunk

**Issue**

The definition of the `chunk` property of `PaginationChunk` in the response says this:

> This array will consist of at most `limit` elements.

But the `limit` parameter is not documented in the `Request` definition.

Synapse [supports the `limit` parameter](https://github.com/element-hq/synapse/blob/59a15da43364c6b3319983e68f686750a918ec9a/synapse/rest/client/initial_sync.py#L50-L52) by using [`PaginationConfig`](https://github.com/element-hq/synapse/blob/59a15da43364c6b3319983e68f686750a918ec9a/synapse/streams/config.py#L40).

Construct also [supports the `limit` parameter](https://github.com/matrix-construct/construct/blob/0624b69246878da592d3f5c2c3737ad0b5ff6277/modules/client/initialsync.cc#L94-L99).

Start at the linked GET /initialSync specification section and compare the Request definition with the PaginationChunk response description. Update the request documentation so the supported limit parameter is represented consistently, then verify the rendered specification no longer refers to an undocumented request parameter.

Written by the indexing model from the issue text.