docs: add llms.txt file (#745)

## Description

This PR adds `llms.txt` file to our docs - `llms.txt` is built
automatically using [docusaurus-plugin-llms-txt
plugin](https://www.npmjs.com/package/@signalwire/docusaurus-plugin-llms-txt/v/1.2.2).
Because of some bug regarding absolute urls in the plugin used, this PR
also adds `postbuild` script that fixes duplicated url slugs in the
`llms.txt` file.

### Introduces a breaking change?

- [ ] Yes
- [x] No

### Type of change

- [ ] Bug fix (change which fixes an issue)
- [ ] New feature (change which adds functionality)
- [x] Documentation update (improves or adds clarity to existing
documentation)
- [ ] Other (chores, tests, code style improvements etc.)

### Tested on

- [ ] iOS
- [ ] Android

### Testing instructions

- build docs locally (`yarn build -> yarn serve`)
- verify `/react-native-executorch/llms.txt` url

### Screenshots

[llms.txt](https://github.com/user-attachments/files/24794966/llms.txt)
<img width="1720" height="949" alt="Screenshot 2026-01-22 at 13 52 51"
src="https://github.com/user-attachments/assets/b3c33a8b-aaea-47dd-b461-88a3a384e099"
/>

### Related issues

#416 

### Checklist

- [ ] I have performed a self-review of my code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have updated the documentation accordingly
- [ ] My changes generate no new warnings

### Additional notes

After merging this PR, our DocSearch crawler configuration should be
updated, so is does not index `llms.txt` file.

Author: mateuszlampert

docs/docusaurus.config.js

@@ -121,6 +121,30 @@ const config = {
       enableSidePanel: true,
     },
   },
+  plugins: [
+    [
+      '@signalwire/docusaurus-plugin-llms-txt',
+      /** @type {import('@signalwire/docusaurus-plugin-llms-txt').PluginOptions} */
+      ({
+        siteTitle: 'React Native ExecuTorch',
+        siteDescription:
+          "React Native ExecuTorch brings Meta's ExecuTorch AI framework into the React Native ecosystem, enabling developers to run AI models and LLMs locally, directly on mobile devices. It provides a declarative API for on-device inference, allowing you to use local AI models without relying on cloud infrastructure. Built on the ExecuTorch foundation - part of the PyTorch Edge ecosystem - it extends efficient on-device AI deployment to cross-platform mobile applications in React Native.",
+        depth: 3,
+        enableDescriptions: true,
+        content: {
+          includeVersionedDocs: false,
+          relativePaths: false,
+          enableMarkdownFiles: false,
+          excludeRoutes: ['**/react-native-executorch/search'],
+        },
+        includeOrder: [
+          '**/docs/!(category|benchmarks)**',
+          '**/docs/benchmarks/**',
+          '**/docs/category/**',
+        ],
+      }),
+    ],
+  ],
 };
 
 module.exports = config;

docs/package.json

@@ -5,7 +5,8 @@
   "scripts": {
     "docusaurus": "docusaurus",
     "start": "docusaurus start",
-    "build": "docusaurus build",
+    "build": "docusaurus build && npm run postbuild",
+    "postbuild": "node scripts/postbuild.mjs",
     "swizzle": "docusaurus swizzle",
     "deploy": "docusaurus deploy",
     "clear": "docusaurus clear",
@@ -25,6 +26,7 @@
     "@emotion/styled": "^11.14.1",
     "@mdx-js/react": "^3.0.0",
     "@mui/material": "^7.3.7",
+    "@signalwire/docusaurus-plugin-llms-txt": "^1.2.2",
     "@swmansion/t-rex-ui": "^1.2.1",
     "clsx": "^2.1.0",
     "copy-text-to-clipboard": "^3.2.2",

docs/scripts/postbuild.mjs

@@ -0,0 +1,19 @@
+import { join, dirname } from 'path';
+import { fileURLToPath } from 'url';
+import { fixLLMsTxtDuplicatedPaths } from './tasks/fix-llms-txt.mjs';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+const BUILD_DIR = join(__dirname, '..', 'build');
+
+async function postbuild() {
+  try {
+    fixLLMsTxtDuplicatedPaths(BUILD_DIR);
+    console.log('All post-build tasks completed successfully.\n');
+  } catch (error) {
+    console.error('\nPost-build script failed:', error);
+    process.exit(1);
+  }
+}
+
+postbuild();

docs/scripts/tasks/fix-llms-txt.mjs

@@ -0,0 +1,38 @@
+import { existsSync, readFileSync, writeFileSync } from 'fs';
+import { join, dirname } from 'path';
+import { fileURLToPath } from 'url';
+
+export { fixLLMsTxtDuplicatedPaths };
+
+const FILES_TO_FIX = ['llms.txt'];
+const DUPLICATED_PATH = '/react-native-executorch/react-native-executorch/';
+const FIXED_PATH = '/react-native-executorch/';
+
+function fixLLMsTxtDuplicatedPaths(buildDir) {
+  console.log('Running LLMS.txt fix script...');
+  console.log(`Looking in: ${buildDir}`);
+
+  FILES_TO_FIX.forEach((fileName) => {
+    const filePath = join(buildDir, fileName);
+
+    if (existsSync(filePath)) {
+      try {
+        const content = readFileSync(filePath, 'utf8');
+
+        if (content.includes(DUPLICATED_PATH)) {
+          const fixedContent = content.replaceAll(DUPLICATED_PATH, FIXED_PATH);
+
+          writeFileSync(filePath, fixedContent, 'utf8');
+          console.log(`Fixed URLs in ${fileName}`);
+        } else {
+          console.info(`No broken URLs found in ${fileName}`);
+        }
+      } catch (err) {
+        console.error(`Could not process ${fileName}:`, err);
+        process.exit(1);
+      }
+    } else {
+      console.warn(`File ${fileName} not found`);
+    }
+  });
+}