feat: add title, summary and description fields to the core models (#315)

Author: magicmatatjahu

definitions/3.0.0/channel.json

@@ -20,9 +20,17 @@
         "$ref": "http://asyncapi.com/definitions/3.0.0/parameter.json"
       }
     },
+    "title": {
+      "type": "string",
+      "description": "A human-friendly title for the channel."
+    },
+    "summary": {
+      "type": "string",
+      "description": "A brief summary of the channel."
+    },
     "description": {
       "type": "string",
-      "description": "A description of the channel."
+      "description": "A longer description of the channel. CommonMark is allowed."
     },
     "servers": {
       "type": "array",

definitions/3.0.0/operation.json

@@ -51,11 +51,17 @@
         ]
       }
     },
+    "title": {
+      "type": "string",
+      "description": "A human-friendly title for the operation."
+    },
     "summary": {
-      "type": "string"
+      "type": "string",
+      "description": "A brief summary of the operation."
     },
     "description": {
-      "type": "string"
+      "type": "string",
+      "description": "A longer description of the operation. CommonMark is allowed."
     },
     "security": {
       "type": "array",

definitions/3.0.0/operationTrait.json

@@ -13,6 +13,9 @@
     "channel": {
       "$ref": "http://asyncapi.com/definitions/3.0.0/operation.json#/properties/channel"
     },
+    "title": {
+      "$ref": "http://asyncapi.com/definitions/3.0.0/operation.json#/properties/title"
+    },
     "summary": {
       "$ref": "http://asyncapi.com/definitions/3.0.0/operation.json#/properties/summary"
     },

definitions/3.0.0/server.json

@@ -15,8 +15,17 @@
     "url": {
       "type": "string"
     },
+    "title": {
+      "type": "string",
+      "description": "A human-friendly title for the server."
+    },
+    "summary": {
+      "type": "string",
+      "description": "A brief summary of the server."
+    },
     "description": {
-      "type": "string"
+      "type": "string",
+      "description": "A longer description of the server. CommonMark is allowed."
     },
     "protocol": {
       "type": "string",