markdown export from URL (#5830)

* Add Markdown export of any doc page by appending `.md` to the URL
* New "View as Markdown" dropdown menu from the "copy page" button

documentation/scripts/serve-static.js

@@ -0,0 +1,51 @@
+#!/usr/bin/env node
+
+/**
+ * Simple static file server for testing markdown exports locally.
+ * Unlike `docusaurus serve`, this serves files as-is without routing logic.
+ */
+
+const http = require('http');
+const serveStatic = require('serve-static');
+const path = require('path');
+
+const buildDir = path.join(__dirname, '..', 'build');
+const port = process.env.PORT || 3001;
+
+const serve = serveStatic(buildDir, {
+  index: ['index.html'],
+  setHeaders: (res, filePath) => {
+    // Set proper content type for markdown files
+    if (filePath.endsWith('.md')) {
+      res.setHeader('Content-Type', 'text/plain; charset=utf-8');
+    }
+  }
+});
+
+const server = http.createServer((req, res) => {
+  // Handle requests to /goose/ by serving from the build directory
+  if (req.url.startsWith('/goose/')) {
+    // Strip /goose/ prefix and serve the file
+    req.url = req.url.substring(6); // Remove '/goose'
+    serve(req, res, () => {
+      res.statusCode = 404;
+      res.end('Not found');
+    });
+  } else if (req.url === '/') {
+    // Redirect root to /goose/
+    res.writeHead(302, { Location: '/goose/' });
+    res.end();
+  } else {
+    // For any other path, return 404
+    res.statusCode = 404;
+    res.end('Not found - try /goose/');
+  }
+});
+
+server.listen(port, () => {
+  console.log(`\n🚀 Static file server running at http://localhost:${port}`);
+  console.log(`\n🏠 Homepage: http://localhost:${port}/goose/`);
+  console.log(`\n📝 Test markdown exports:`);
+  console.log(`   http://localhost:${port}/goose/docs/quickstart.md`);
+  console.log(`   http://localhost:${port}/goose/docs/getting-started/installation.md\n`);
+});