Add full automotive RTOS project

Add kernel (Cortex-M0/M3/M4, Tricore, S32K, RISC-V ports), drivers,
middleware (CAN stack, diagnostics, safety), applications, board
support, build/test tooling, and documentation.

CONTRIBUTING.md

@@ -0,0 +1,26 @@
+# Contributing to Automotive RTOS
+
+First off, thank you for considering contributing to Automotive RTOS!
+
+## Table of Contents
+
+- [Code of Conduct](#code-of-conduct)
+- [Getting Started](#getting-started)
+- [Development Process](#development-process)
+- [Coding Standards](#coding-standards)
+- [Testing](#testing)
+- [Documentation](#documentation)
+- [Submitting Changes](#submitting-changes)
+- [Review Process](#review-process)
+
+## Code of Conduct
+
+This project adheres to a Code of Conduct. By participating, you are expected to uphold this code.
+
+## Getting Started
+
+1. Fork the repository
+2. Clone your fork:
+   ```bash
+   git clone https://github.com/your-username/automotive-rtos.git
+   cd automotive-rtos