Feature/setup actions

[simonschuhmacher]

• Setup GitHub Actions for CI & CI/CD
  • Pushes on all branches except main will trigger Run CI which runs:
    • npm ci
    • npm run lint
    • npm run type-check
    • npm run package (builds the project)
  • Tag pushes starting with v (e.g., 0.0.1-alpha.6) will trigger Run CI/CD which runs:
    • npm ci
    • npm run lint
    • npm run type-check
    • npm run publish (publishes distributable packages / installers to GitHub Release)
• Actions run on a matrix, consisting of the following images (both CI and CI/CD)
  • macOS-latest
  • windows-latest
  • ubuntu-latest
• The publish action will automatically create a release on GitHub (tag needs to be existing already)
• Version of git tag and version in package.json should match!
• Packages are created for all supported architectures by electron (x64, arm64, ia32, armv7l)
• Cleaned up package.json-metadata a bit

Closes #7

[triumphvalley]

looks good, it currently does not work on my mac to install and run the app -> #20. I will merge nontheless, so we have the checks enabled on the other branches.