Update LICENSE copyright and add AI attribution instructions

[jerrysxie]

This PR applies two org-wide standardisation changes
(ref: OpenDevicePartnership/embedded-rust-template#20):

1. LICENSE – normalise the copyright line to:
   Copyright (c) Open Device Partnership and Contributors

[Copilot]

Pull request overview

This PR applies org-wide standardization updates by (1) normalizing the MIT LICENSE copyright line to a yearless “Open Device Partnership and Contributors” form and (2) documenting commit message and AI attribution expectations for contributors/agents in the repo’s Copilot instructions.

Changes:

• Update LICENSE copyright notice to Copyright (c) Open Device Partnership and Contributors.
• Add commit message conventions and an Assisted-by: trailer format under .github/copilot-instructions.md for consistent AI attribution guidance.

Reviewed changes

Copilot reviewed 1 out of 1 changed files in this pull request and generated no comments.

File	Description
LICENSE	Standardizes the MIT license copyright line to the org-wide “Open Device Partnership and Contributors” wording.
.github/copilot-instructions.md	Documents commit message conventions and AI attribution requirements (Assisted-by trailer) for consistency across repos.