[Chapel Merge] Writeup on a new implementation for interfaces

Branch: refs/heads/main
Revision: 1e5cdbd
Author: vasslitvinov
Log Message:

Merge pull request #18063 from vasslitvinov/ifc-new-strategy

Writeup on a new implementation for interfaces

This adds a document that reviews the aspects of implementation
that need to cater to interfaces and outlines a new implementation
direction for interfaces.

Modified Files:
A doc/rst/developer/implementation/Interfaces-new.md

Compare: https://github.com/chapel-lang/chapel/compare/a6a8ed23e80a...1e5cdbd122e0