[Docs] Improve README: POS setup guide, screenshots, supported hardware

[islandbitcoin]

💰 Bounty — ⚡ Spark (5,000 sats)

What needs to be done:

• Add a clear setup guide for running the Flash POS app locally
• Include screenshots of the main screens (payment, transaction history, settings)
• Document supported hardware (receipt printers, NFC readers if applicable)
• Add a "Getting Started" section for new contributors

Acceptance Criteria:

• README has local dev setup instructions (iOS + Android)
• At least 3 screenshots of key screens
• Supported hardware section
• Getting started / contribution section
• Clean markdown, no broken links

Payment: 5,000 sats via Lightning on merge. See CONTRIBUTING.md for details.

[forge0x]

Hey! Found this bounty and would love to take a crack at it. 👋

I've been working with React Native for a few years and have contributed docs to a few other open-source projects. The Flash POS README is pretty bare-bones right now — no setup instructions, no screenshots, nothing for new contributors.

I can knock out all the acceptance criteria:

• Local dev setup for iOS + Android
• Screenshots of key screens
• Supported hardware section
• Getting started / contribution section

Is this still available? Happy to start right away. For payment I'll provide a Cashu ecash address (forge.flashapp.me mint).

[patoo0x]

📋 Definition of Done — 💰 5,000 sats

Expected Behavior After Fix:

• README clearly describes what Flash POS is and who it's for
• Local dev setup instructions for both iOS and Android
• Screenshots of key screens (placeholder refs acceptable for initial PR)
• Supported hardware section (receipt printers, NFC readers, device requirements)
• Getting started section for new contributors with link to CONTRIBUTING.md
• Clean markdown, no broken links

Deliverables:

• PR against main referencing this issue (closes #49)
• Lightning address provided in your first comment on this issue

Review Gate:

• Nick signs off
• Dread final approval

Payment: 5,000 sats via Lightning on merge.
See CONTRIBUTING.md for full details.

[forge0x]

Hey! I'd like to claim this bounty. I've already submitted PR #51 with the improved README.

Lightning address for payment: forge0x@primal.net

Ready for review! ⚡

[forge0x]

Updated Lightning address: npub1pucn2v3g4hjgvlc29c5ep44s9ct0zuj827d86exzraglxzmqf0lsp482wl@npub.cash

Working on getting actual screenshots now — will update the PR shortly.