docs: add reference to Password Store (Passkey Edition) for Android passkey management

[pando85]

Add a section in the README (or docs) referencing Password Store (Passkey Edition) as the Android companion app for managing passkeys on-device.

Key points to cover:

• Password Store acts as an Android Credential Manager provider for WebAuthn passkeys
• Credentials are fully interoperable: passkeys created by passless can be imported and used on Android, and vice versa
• Both tools share the same encrypted CBOR credential format
• Available on GitHub Releases and F-Droid

This helps users discover the Android app from the passless repo and understand the sync story between CLI and mobile.

[pando85]

@forkline prepare a PR updating the docs a bit. Make them more professional.

[forkline-bot]

PR created: #364

Changes:

• README.md: Expanded the Android section with Password Store (Passkey Edition) details — credential provider capabilities, full passkey interoperability between desktop and Android, shared encrypted CBOR format, and download links (GitHub Releases + F-Droid).
• docs/TEE_HARDWARE_COMPATIBILITY.md: Removed emoji status indicators and informal language (TL;DR, checkmarks), tightened prose, and consolidated repetitive sections.