Rename Module (λchat)

[jazzz]

Problem

The project's working name was originally "chat_sdk," so the module was labeled chat_sdk with the expectation it would change later. The 'sdk' portion is irrelevant and adds noise.

Solution

Rename the module to λchat and update all references.

While unconventional, this name is short, memorable, and guaranteed not to conflict in other contexts. With auto-complete prevalent in most developer environments, the friction is minimal.

Notes

• The name isn't final and can be easily changed later. The goal here is incremental improvement.
• There is a competing PR here