Add SoCDAML Part III: hands-on lab for adding a new int8 operator

[viv-eth]

This PR adds Part III to Tutorials/SoCDAML.md, a 1-hour hands-on lab in which students add a new int8 operator (iLeakyReLU) to Deeploy and progressively optimize it on Siracusa from a plain-C scalar kernel running on a single core all the way to a tiled, multi-core, XPULP-SIMD kernel. The lab walks through the full compiler pipeline that Parts I and II used as a black box: Parser → Mapper → Binding → Template → TileConstraint → SIMD kernel. Students measure end-to-end cycles at every step and observe the speedup compared to the baseline implementation.

Two coordinated artifact directories ship alongside the markdown:

• Tutorials/PartIII_skeletons/iLeakyReLU/: student starting kit with TODO(student) markers and per-file destination paths.
• Tutorials/PartIII_solution/iLeakyReLU/: full TA reference (kernels, parser, template, tile constraint, ONNX + golden tensors) plus a one-shot deploy.sh that patches the live source tree (Parsers.py, Bindings.py, Tiler.py, Platform.py, DeeployPULPMath.h) and copies the new kernel/template/constraint files into place. Re-runnable in scalar / simd / undo modes.

Added

• Tutorials/PartIII_skeletons/iLeakyReLU/: 8 skeleton files (generate.py, kernel + SIMD kernel skeletons, parser/template/tile-constraint skeletons, header, README).
• Tutorials/PartIII_solution/iLeakyReLU/: full working reference operator (parser, template, tile + perf constraint, scalar + SIMD kernels, header, ONNX + golden artifacts, deploy.sh, README).
• New Part III: Adding a New Operator section appended to Tutorials/SoCDAML.md with 6 stepwise tasks and solution dropdowns matching Parts I/II.

Changed

• Tutorials/SoCDAML.md: appended Part III. Parts I and II are untouched.

Fixed

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