add my Waveshare RP2350-Touch-2.8 case design link and license info

[juliadin]

What

add a new device case for the waveshare trusted display target, link it and add it to the explanatory passage about licensing.

How it was tested

• Host-only change (CLI / docs / CI) — no device behavior touched

Checklist

• [N/A] Device behavior / image changed → config.device_release (bcdDevice) bumped by one (hex)
  in firmware/src/main.rs — host-only (CLI / docs / CI / build) does not (CONTRIBUTING.md)
• [N/A] Fixes something a downgrade would reopen → flag whether the next release should advance the
  rollback epoch (docs/production.md, stage 3) — a seal-time --rollback call, not a code bump
• [N/A] New or changed unsafe → justified in docs/unsafe.md
• [N/A] User-visible behavior → the matching guide under docs/ updated
• [N/A] New files carry the SPDX header (AGPL-3.0-only)
• Commit messages use the zone prefix style (fido:, piv:, rsk:, docs:, …)

[juliadin]

Thanks 💜