Write a design document detailing the communication between LS extensions and dependents to Python extension

[karthiknadig]

This will be a reference on how the overall communication occurs. The intent of this is for future LS extensions to contribute their LS to python extension.

[karthiknadig]

This model has now changed. closing this. We are going to look at a more simplified approach as we plan on moving Jedi to its own extension for better configuration and maintenance.