Docs: Convert the make your Express app cloud native tutorial

[helenmasters]

Convert the following tutorial to Markdown https://medium.com/appsody/nodejs-express-enablement-f6fc2609bc00.

Test all the steps are still current and work, including upping any referenced versions to the current stack levels, if relevant.

[helenmasters]

@sam-github I've taken a look at the next Express tutorial and the steps within it. Following on from the previous tutorial which you reviewed this one also refers (in Step 3) to exporting the Express.js object from the file as module.export.app, unsurprisingly this doesn't work:

"Export the Express.js app object from the file as module.exports.app: The last line of the app.js file should become:

module.exports.app = app;

This exposes the app object so that the nodejs-express Appsody stack can apply it onto its own pre-configured Express.js server that includes the cloud-native capabilities."

Please can you suggest:

1. an adaptation to the wording at the end of Step 2 which is currently:

"Here main references app.js as that is the file that contains the Express.js app object. The next step is to export the app object from that file."

and

2. some replacement code and wording for Step 3.

Thanks!

[sam-github]

module.exports.app = app; would likely become module.exports = () => app;

[helenmasters]

@ddunn2 I've made some text updates to this tutorial from medium in line with Sam's comments (and to line it up with the other tutorial I converted). I've emailed the file to you for formatting, adding front matter and running through to check it all works.

When you're done please can you raise a PR and make myself and Sam Roberts the reviewers. Thanks!

[helenmasters]

Closing as this is now complete.