Describe the bug

Recently a user tried to run Headlamp for the first time and also build a plugin from scratch. They gave me this feedback:

Problems when running headlamp-plugin

• Running npx @kinvolk/headlamp-plugin create takes a long time
  Maybe we cannot solve it but we could look into it at least
• Creating a plugin outputs lots of deprecated warnings and engine incompatibility
  Some deprecations are inevitable, and the engines incompatibility is something the user needs to take care of, but we should lower the number of packages that are deprecated

Outdated/invalid docs

• Building & Shipping plugins seems outdated

  • Doesn't e.g. mention that plugins have a package.json and a main.js
  • Doesn't mention deploying plugins using gitops like we have in the flux example, which many users seem to like
  • Seems unrelated to the Creating a Plugin section

• The How to Create a Plugin section starts mentioning types...

  • There's no mention of the dependencies that are needed (node)

Seems like we need to rethink these sections, maybe make them into one.

More context to take into account

• Cover more basic steps
  • Mention e.g. that the plugins can be created in any place, likely in a user's favorite projects folder or something
  • We need people with little experience to be able to understand the process of zero-to-a-headlamp-plugin