docs: showcase Flare features in the README

[FlintSH]

What does your PR do?

Gives the README a clearer introduction and eight collapsed feature sections covering uploads, previews, search, pastes and short links, appearance, integrations, accounts, and self-hosting. Six viewport screenshots from v2.0.0 show the features without making the initial page long.

Why are you making these changes?

Help first-time visitors understand what Flare does, see what they can make their own, and find a deployment path immediately.

How did you implement it?

Reorganized the README around a short introduction, direct navigation, and native GitHub <details> sections. Added links to the feature guides and updated the inline Docker example to use docker compose, while keeping the account-email and OIDC setup guidance.

Screenshots / Recordings (if UI)

Preview the updated README.

Related Issues

None.

Additional Info

Validated with GitHub's Markdown renderer and desktop/mobile browser checks: all screenshots load, sections toggle and start collapsed, and the page has no horizontal overflow at 390px. Checked section anchors, relative links, and the rendered Compose YAML. Prettier and git diff --check pass. Documentation-only change; application tests were not run.

[github-actions]

Flare PR preview: expired

The 24-hour preview lifetime ended. A new commit or a re-run of the image workflow creates a fresh preview.

Commit: 79e51695515b
Image build and logs

Public, disposable test instance running untrusted PR code. Anyone can view or change its test data. Do not enter passwords you use elsewhere, credentials, or private files.

[alwaysmeticulous]

✅ Meticulous evaluated 50 user flows and determined via code coverage that none of them exercise the code changed in this PR, so no replays were executed. View results.

_{Last updated for commit 79e5169 docs: showcase Flare features in the README. This comment will update as new commits are pushed.}

[greptile-apps]

Greptile Summary

Summary

• Refreshed the README with a clearer product introduction, expandable feature walkthroughs, updated Docker Compose setup guidance, and consolidated documentation links.
• The rendered README interactions, navigation anchors, guide link, and Docker Compose example work as intended.
• No issues were found; the change is safe to merge.

Confidence Score: 5/5

Safe to merge: the README changes render and behave correctly in the project page.

No actionable issues were found. The updated disclosures, documentation navigation, and Docker Compose configuration were exercised successfully.

Files Needing Attention: None.

T-Rex Logs

What T-Rex did

• Authored and executed a validation script readme-github-rendering-check.cjs to verify GitHub README rendering behavior.
• Captured the command output log readme-github-rendering-check.log showing source URLs, all assertions, working directory, and exit code 0.
• Recorded before and after GitHub rendering behavior with poster frames to illustrate baseline and changed results.
• Opened and captured the Docker Compose configuration image on GitHub for inspection.

_{Ran code and verified through T-Rex}

Important Files Changed

Filename	Overview
README.md	Reorganizes the product overview, feature showcase, self-hosted deployment instructions, configuration guide links, support information, and license reference.

_{Reviews (1): Last reviewed commit: "docs: showcase Flare features in the REA..." | Re-trigger Greptile}