Prepare materials helping to build devfile

[tsmaeder]

@slemeur asked us to give a presentation to some folks to show them how we make devfiles for a particular technology.

The idea is to make give a presentation based on the Quarkus devfile we're working on that shows what needs to be done to have a working devfile for Quarkus.
As a by-product, we want to make a blog post about the same content. Just a couple of ideas of what we need to cover:

• Start with an existing workspace
• Find/Create a developer image we can use to build applications for the technology
  • Fix it to run on OpenShift (add user-hack)
• Add che plugins you need, remove che plugins you don't. (new plugins not covered)
• Add a link to a sample
• Add commands, test them in the workspace
• Add debug configurations, tasks, etc.
• Persistent volumes, what do you need? (Example: .m2 folder)

[tsmaeder]

Presentation given and shared video: CEE folks writing blog post.