feat: add ssh key setup step

[jsgalarraga]

Description

feat: add ssh_key secret input

Fixes #106

Type of Change

• ✨ New feature (non-breaking change which adds functionality)
• 🛠️ Bug fix (non-breaking change which fixes an issue)
• ❌ Breaking change (fix or feature that would cause existing functionality to change)
• 🧹 Code refactor
• ✅ Build configuration change
• 📝 Documentation
• 🗑️ Chore

[alestiago]

Thanks for the contribution 💙

LGTM, although I have not tested it. Did you get a chance to test it out?

[jsgalarraga]

@alestiago Yes, I did test it with and without using the new secret input. In both scenarios worked correctly.

[xkxeeshankhan]

@jsgalarraga Hey man thanks for this but when I try to add the ssh_key I get he below error from the github Actions

Invalid secret, ssh_key is not defined in the referenced workflow.

yaml Snip;

build:
    uses: VeryGoodOpenSource/very_good_workflows/.github/workflows/flutter_package.yml@v1
    secrets:
      ssh_key: ${{secrets.UI_SSH_KEY}}