Add Zecd, Nozy, and Zipher to Zcash Wallets directory

[DanielDerefaka]

Add Zcash wallets to the Wallets directory

Adds three Zcash wallets to site/Using_Zcash/Wallets.md, using the existing entry format (Devices, Operating System, Wallet Support, Pools, Features):

• Zecd — a shielded-first Zcash wallet server by Zec.rocks that speaks the Bitcoin Core JSON-RPC dialect (Linux / Docker).
• Nozy — an Orchard-only, fully-shielded CLI wallet by LEONINE-DAO (Windows / Linux / macOS).
• Zipher — a mobile (iOS / Android) + CLI wallet by Atmosphere Labs with shielding, DEX swaps and NEAR Intents.

All attributes were verified against each project's official site, GitHub repo, and Zcash forum announcements. Logos are linked from official/first-party sources.

Notes

• The original request also listed a wallet named "Zend: Zcash Wallet", but it could not be verified from any source (Zcash forum, app stores, GitHub, ZecHub, general web), so it is intentionally omitted from this PR. Happy to add it in a follow-up once an official link is available.
• The request spelled the third wallet "Nozzy"; the project's actual name is Nozy (repo: LEONINE-DAO/Nozy-wallet), so it is listed as Nozy for accuracy.