chore(build): try to build demo and docs (#3434)

platform/app/preinstall.js

@@ -0,0 +1,13 @@
+console.log('preinstall.js');
+
+const { exec } = require('child_process');
+const log = (err, stdout, stderr) => console.log(stdout);
+
+const GITHUB_TOKEN = process.env.GITHUB_TOKEN;
+if (GITHUB_TOKEN) {
+  const command = `git config --global url."https://${GITHUB_TOKEN}:x-oauth-basic@github.com/".insteadOf ssh://git@github.com/`;
+  console.log(command);
+  exec(command, log);
+} else {
+  console.log('No GITHUB_TOKEN found, skipping private repo customization');
+}