Add Firefly v1.0.0

[rajivshah3]

Important: Do not tick a checkbox if you haven’t performed its action. Honesty is indispensable for a smooth review process.

After making all changes to a cask, verify:

• The submission is for a stable version or documented exception.
• brew audit --cask {{cask_file}} is error-free.
• brew style --fix {{cask_file}} reports no offenses.

Additionally, if adding a new cask:

• Named the cask according to the token reference.
• Checked the cask was not already refused.
• Checked the cask is submitted to the correct repo.
• brew audit --new-cask {{cask_file}} worked successfully.
• brew install --cask {{cask_file}} worked successfully.
• brew uninstall --cask {{cask_file}} worked successfully.

[miccal]

Thank you @rajivshah3.