fix(spec): add RFC for unambiguous Channel Item referencing

Refs #607

Author: char0n

spec/asyncapi.md

@@ -565,7 +565,7 @@ Describes the operations available on a single channel.
 
 Field Name | Type | Description
 ---|:---:|---
-<a name="channelItemObjectRef"></a>$ref | `string` | Allows for an external definition of this channel item. The referenced structure MUST be in the format of a [Channel Item Object](#channelItemObject). If there are conflicts between the referenced definition and this Channel Item's definition, the behavior is *undefined*.
+<a name="channelItemObjectRef"></a>$ref | `string` | Allows for an external definition of this channel item. The referenced structure MUST be in the format of a [Channel Item Object](#channelItemObject). If there are conflicts between the referenced definition and this Channel Item's definition, the behavior is *undefined*. <br><br>**Deprecated:** Usage of the `$ref` property has been deprecated.
 <a name="channelItemObjectDescription"></a>description | `string` | An optional description of this channel item. [CommonMark syntax](https://spec.commonmark.org/) can be used for rich text representation.
 <a name="channelItemObjectServers"></a>servers | [`string`] | The servers on which this channel is available, specified as an optional unordered list of names (string keys) of [Server Objects](#serverObject) defined in the [Servers Object](#serversObject) (a map). If `servers` is absent or empty then this channel must be available on all servers defined in the [Servers Object](#serversObject).
 <a name="channelItemObjectSubscribe"></a>subscribe | [Operation Object](#operationObject) | A definition of the SUBSCRIBE operation, which defines the messages produced by the application and sent to the channel.
@@ -1435,10 +1435,10 @@ All objects defined within the components object will have no effect on the API
 ##### Fixed Fields
 
 Field Name | Type | Description
----|:---|---
+---|:---|--- 
 <a name="componentsSchemas"></a> schemas | Map[`string`, [Schema Object](#schemaObject) \| [Reference Object](#referenceObject)] | An object to hold reusable [Schema Objects](#schemaObject).
 <a name="componentsServers"></a> servers | Map[`string`, [Server Object](#serverObject) \| [Reference Object](#referenceObject)] | An object to hold reusable [Server Objects](#serverObject).
-<a name="componentsChannels"></a> channels | Map[`string`, [Channel Object](#channelItemObject) \| [Reference Object](#referenceObject)] | An object to hold reusable [Channel Objects](#channelItemObject).
+<a name="componentsChannels"></a> channels | Map[`string`, [Channel Item Object](#channelItemObject)] | An object to hold reusable [Channel Item Objects](#channelItemObject).
 <a name="componentsMessages"></a> messages | Map[`string`, [Message Object](#messageObject) \| [Reference Object](#referenceObject)] | An object to hold reusable [Message Objects](#messageObject).
 <a name="componentsSecuritySchemes"></a> securitySchemes| Map[`string`, [Security Scheme Object](#securitySchemeObject) \| [Reference Object](#referenceObject)] | An object to hold reusable [Security Scheme Objects](#securitySchemeObject).
 <a name="componentsParameters"></a> parameters | Map[`string`, [Parameter Object](#parameterObject) \| [Reference Object](#referenceObject)] | An object to hold reusable [Parameter Objects](#parameterObject).