If you follow the readme procedure, the following error will occur in the first npm install express.
saveError ENOENT: no such file or directory, open '/xxx/xxx/package.json'
As you know, the cause is
package.json does not exist.
Other users seem to have a similar error, so it seems better to add
npm init to the readme.
Or I thought it would be nice to bring a link
Please follow the installation guide for details before
npm install express.