Add illustrated Chinese tutorial '图解计算机原理' and link it from README - #3

Motivation

• Provide a concise, diagram-first tutorial that helps engineers understand the full run-time chain from power-on to application behavior for embedded and systems engineers.
• Make the new tutorial discoverable from the repository root so contributors can quickly find the learning resource.

Description

• Add a new file docs/computer-principles-illustrated.md containing a structured, diagram-led Chinese tutorial covering CPU, memory, compilation/linking, startup, buses/peripherals, interrupts, DMA, RTOS, storage, networking, debugging, experiments, and a复盘 template.
• Update README.md to add a Tutorials section that links to the new document via docs/computer-principles-illustrated.md.
• Keep content engineering-focused with concrete verification tasks, debugging/checklist guidance, and experiment suggestions to form verifiable learning/validation loops.

Testing

• Ran a small automated Python check to ensure the markdown files are readable and non-empty and that no tab characters are present using the script: python - <<'PY' ... PY, which passed.
• Ran git diff --cached --check to validate staged markdown for whitespace/trailing-space issues, and the check passed after fixing trailing whitespace.

Codex Task