feat(http): add externalDocs to service, operation, tag definition

see platform-internal issue 15432

Author: EdVinyard

src/graph.ts

@@ -1,4 +1,4 @@
-import { Extensions } from "./http-spec";
+import { Extensions, IExternalDocs } from "./http-spec";
 
 export interface IShareableNode {
   id: string;
@@ -20,6 +20,8 @@ export interface INode extends IShareableNode {
 export interface INodeTag extends IShareableNode {
   name: string;
   description?: string;
+  /** only applicable to tag _definitions_, not references */
+  externalDocs?: IExternalDocs;
 }
 
 export interface INodeVariable {

src/http-spec.ts

@@ -31,6 +31,7 @@ export interface IHttpService extends INode, IShareableNode {
     backgroundColor?: string;
   };
   internal?: boolean;
+  externalDocs?: IExternalDocs;
 }
 
 export interface IBundledHttpService extends Omit<IHttpService, 'securitySchemes'> {
@@ -66,6 +67,7 @@ export interface IHttpOperation<Bundle extends boolean = false> extends INode, I
   securityDeclarationType?: HttpOperationSecurityDeclarationTypes;
   deprecated?: boolean;
   internal?: boolean;
+  externalDocs?: IExternalDocs;
 }
 
 export enum HttpOperationSecurityDeclarationTypes {
@@ -334,3 +336,8 @@ export type Reference = {
 export interface Extensions {
   [key: string]: unknown;
 }
+
+export interface IExternalDocs { 
+  description?: string;
+  url: string;
+}