Replace placeholder README with CassetteLab organization overview

[Copilot]

This updates the repository README from a placeholder to a clear organization profile. It introduces CassetteLab, highlights where projects live, and states the mission to build free/open-source software for people.

• Overview

  • Replaced # .github with a proper CassetteLab landing README.
  • Added a concise intro describing purpose and values.

• Projects section

  • Added a dedicated section pointing readers to CassetteLab repositories.
  • Framed projects as open, practical, and community-driven work.

• Vision section

  • Added a mission statement centered on software that empowers people.
  • Added explicit focus areas: free/open-source development, practical tooling, and collaboration.

# CassetteLab

Welcome to **CassetteLab**.

We build projects that are free and open-source, with a simple goal: create useful software for people.

Original prompt

create a readme file that presents CassetteLab, our projects and our will to build free and OS software for people