Refactor - replace Atom with Pulsar and remove Linux options

[HighHarmonics2]

The script needs to replace Atom with Pulsar and the new version of the tidalcycles package.

[HighHarmonics2]

In discord with yaxu it was determine that macOS would be the only supported OS. Refactoring should be done to remove Linux options. Rationale:

• The Linux Ansible solution is much better for a full stack tidal install on Linux
• Removing Linux options will make this install script easier to support

[HighHarmonics2]

This work will cover multiple steps, including:

• initial stage: disable the Atom installer (done)
• Pulsar - DMG: add download and install via dmg format without tidalcycles package install (zip download
• and package install currently not available)
• refactor script to remove Linux system checks and conditional install logic
• when available: add step to install tidalcycles package for pulsar and change DMG to ZIP
• add support for Apple Silicon

[HighHarmonics2]

Major changes completed to tidal-bootstrap.command.
See the changelog in the file. Some local testing has been done. I'm working on a test env outside of my machine. @yaxu - it would be good for you to review where this branch is at.

[HighHarmonics2]

@76creates Given your interest in this shell script, I would welcome any input or contributions to the refactor we are working on. See the branch "refactor" https://github.com/tidalcycles/tidal-bootstrap/tree/refactor

[HighHarmonics2]

Also made changes to User Documentation to reflect script changes.
See: https://tidalcycles.org/docs/getting-started/macos_install