Add kd-screen-guard library to README

[KhvichaDev]

General

• Pull request template structure not broken

Type

• Fix
• Feature

Checklist

• Title as described
• Make sure you put things in the right category!
• Always add your items to the end of a list

Open Source

• Link description does not contain a link to an author / third-party resource
• The documentation (README) contains a description of the project, illustration of the project with a demo or screenshots and a CONTRIBUTING section
• The documentation is in English.
• The project is active and maintained.
• The project accepts contributions.
• Not a commercial product

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kd-screen-guard is a standalone, zero-dependency, tamper-proof lock screen library with native Vue 3 composables (useScreenGuard):

• WebAuthn Biometrics (Touch ID, Face ID, Windows Hello)
• WebRTC Intruder Snapshot capture
• Off-main-thread Web Worker PBKDF2 cryptography
• Self-healing Anti-Tamper DOM protection

GitHub: https://github.com/KhvichaDev/kd-screen-guard
NPM: https://www.npmjs.com/package/kd-screen-guard