Add a plugin template repo per plugin language

[MartinHjelmare]

Roadmap: CI, contribution guidelines, project management

We want to make it easy for plugin developers to get started and reach a high standard for their plugins. Do this by creating templates for plugins.

• Create a plugin template repo for each plugin language we support:
  • Python
  • JavaScript
• The template repo should contain:
  • Unit tests example and entry point
  • CI for tests
  • CI for code formatting
  • CI for linting