add API reference.

webpage/docusaurus.config.ts

@@ -1,6 +1,8 @@
 import {themes as prismThemes} from 'prism-react-renderer';
 import type {Config} from '@docusaurus/types';
 import type * as Preset from '@docusaurus/preset-classic';
+import type * as Plugin from "@docusaurus/types/src/plugin";
+import type * as OpenApiPlugin from "docusaurus-plugin-openapi-docs";
 
 // This runs in Node.js - Don't use client-side code here (browser APIs, JSX...)
 
@@ -33,6 +35,7 @@ const config: Config = {
       {
         docs: {
           sidebarPath: './sidebars.ts',
+          docItemComponent: "@theme/ApiItem", // Derived from docusaurus-theme-openapi
           editUrl: 'https://github.com/m1k1o/neko/tree/main/docs/',
           lastVersion: 'current',
           versions: {
@@ -72,7 +75,7 @@ const config: Config = {
       items: [
         {
           type: 'docSidebar',
-          sidebarId: 'tutorialSidebar',
+          sidebarId: 'docsSidebar',
           position: 'left',
           label: 'Docs',
         },
@@ -167,6 +170,30 @@ const config: Config = {
       additionalLanguages: ['bash'],
     },
   } satisfies Preset.ThemeConfig,
+
+  plugins: [
+    [
+      "docusaurus-plugin-openapi-docs",
+      {
+        id: "openapi",
+        docsPluginId: "classic",
+        config: {
+          api: {
+            specPath: "../server/openapi.yaml",
+            outputDir: "docs/api",
+            downloadUrl: "https://raw.githubusercontent.com/m1k1o/neko/refs/heads/master/server/openapi.yaml",
+            sidebarOptions: {
+              groupPathsBy: "tag",
+              categoryLinkSource: "tag",
+              sidebarCollapsed: false,
+            },
+          } satisfies OpenApiPlugin.Options,
+        } satisfies Plugin.PluginOptions,
+      },
+    ],
+  ],
+
+  themes: ["docusaurus-theme-openapi-docs"],
 };
 
 export default config;