Added Openreads app

[mateusz-bak]

Please read How to contribute before creating a submission.

Description

PR to add Openreads Flutter app. Link to repo: https://github.com/mateusz-bak/openreads-android Openreads is a simple privacy oriented mobile books tracker using Open Library API.

Checklist

• [x] I read How to contribute
• [x] I edited the SOURCE.md file only
• [x] Added a link to the repo in the PR

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