Planner support

Hello,

We would like to use programmatic access to the Microsoft Planner functionality so we can do some data science on tasks we are performing.

I will be trying to add planner support, I just wanted to know if you were planning this already (pun intended), would be interested in adding that functionality, or if it is out of scope forever.

Start by reviewing the repository's existing R SDK support for Microsoft 365 APIs and identify how a new Planner integration would fit. Clarify the intended Planner task operations and data access before implementation; done means programmatic Planner support is available for analyzing tasks.

Written by the indexing model from the issue text.