GET /directory/room/:alias should say words about resident servers, not knowledgeable ones

Link: https://spec.matrix.org/v1.13/client-server-api/#get_matrixclientv3directoryroomroomalias

It currently says 'servers that are aware of the room alias': no servers are going to be aware of it except the directory server, the others are meant to resolve it. It should say resident servers instead.

Open the linked Matrix Client-Server API section for GET /_matrix/client/v3/directory/room/{roomAlias} and locate the phrase about servers being aware of the room alias. Update the wording to refer to resident servers, then verify the specification text clearly describes the intended servers.

Written by the indexing model from the issue text.