Respect preferred color scheme in docs (#1241)

docs/docusaurus.config.js

@@ -2,7 +2,7 @@ const lightCodeTheme = require('prism-react-renderer/themes/github');
 const darkCodeTheme = require('prism-react-renderer/themes/dracula');
 const path = require('path');
 
-/** @type {import('@docusaurus/types').DocusaurusConfig} */
+/** @type {import('@docusaurus/types').Config} */
 module.exports = {
   title: 'Woodpecker CI',
   tagline: 'Woodpecker is a simple CI engine with great extensibility.',
@@ -14,7 +14,9 @@ module.exports = {
   organizationName: 'woodpecker-ci',
   projectName: 'woodpecker-ci.github.io',
   trailingSlash: false,
-  themeConfig: {
+  themeConfig:
+    /** @type {import('@docusaurus/preset-classic').ThemeConfig} */
+    ({
       navbar: {
         title: 'Woodpecker',
         logo: {
@@ -137,7 +139,10 @@ module.exports = {
         minHeadingLevel: 2,
         maxHeadingLevel: 4,
       },
+      colorMode: {
+        respectPrefersColorScheme: true,
       },
+    }),
   plugins: [
     () => ({
       name: 'docusaurus-plugin-favicon',
@@ -177,7 +182,8 @@ module.exports = {
   presets: [
     [
       '@docusaurus/preset-classic',
-      {
+      /** @type {import('@docusaurus/preset-classic').Options} */
+      ({
         docs: {
           sidebarPath: require.resolve('./sidebars.js'),
           editUrl: 'https://github.com/woodpecker-ci/woodpecker/edit/master/docs/',
@@ -197,7 +203,7 @@ module.exports = {
         theme: {
           customCss: require.resolve('./src/css/custom.css'),
         },
-      },
+      }),
     ],
   ],
   webpack: {