Create a list of functionality which Dapplo.Jira doesn't support or is obsoleted / removed in the JIRA Endpoints.

[Lakritzator]

As a developer I would like to know what functionality still needs to be added to this library to have a good coverage of that which Atlassian makes possible via their JIRA API.

Additionally, for the current coverage of functionality in this library, I need to know what is no longer supported or still missing fields and information.

Write this down in a markdown file, with links to the documentation or Atlassian and corresponding files in this project.
A bonus would be to have the description in such a way that I can use it to request this as a feature request where Copilot can work on.