How to extend PyCharm projects?


I am looking into bringing some custom “framework” support to a PyCharm plugin.
I heavily use IntelliJ IDEA and thought that a facet would be the right thing. Unfortunately the target audience is using PyCharm thus the decision to target this platform instead.
I looked into several examples like project-wizard, module-types, design-and-implement-wizard-steps and none of these seem to work for PyCharm (I added the super simple project wizard step and the builder is even called at all; hooked the debugger into `isAvailable` and `getModuleType`). I understand these are all for IntelliJ.
I had a look at the PyCharm docs and they are not very resourceful. It points to intellij-community-plugins-extension-point-list which has a super short paragraph about extension points which basically only points to the platform explorer which does not look like a comprehensive place for getting started.

Question 1: What page is the entry point to PyCharm plugin development and how do I understand what is applicable to PyCharm when I look at the platform documentation?

Question 2: Are there examples on how to extend the PyCharm project wizard or how to add a framework to PyCharm (I understand the Django plugin does it; it does not seem to be open source).