setup Crystal action for GitHub Actions.

setup-crystal-action must execute on Linux or macOS, because I do not know usage that WSL on GitHub Actions.

name: CI

on: 
  push:
    branches:    
    - master
  pull_request:
    branches:
    - master

jobs:
  example:
    runs-on: ubuntu-20.04
    steps:
      - uses: MeilCli/setup-crystal-action@v4
        with: 
          crystal_version: latest
          shards_version: latest
      - name: Run Crystal
        run: |
          echo 'puts "Hello Crystal"' > hello.cr
          crystal run hello.cr

You can also pin to a specific release version in the format @v4.x.x

• crystal_version
  • required
  • install crystal version
  • value: latest or version value, see crystal-lang/crystal
  • default: latest
  • warning:
    • latest sometimes cannot find crystal binary when immediately after release
• shards_version
  • required
  • install shards version
  • value: latest or skip or version value, see crystal-lang/shards
    • if set skip, not install shards
  • default: latest
• github_token
  • github token, using get GitHub Release of crystal-lang/crystal or crystal-lang/shards
  • default: ${{ github.token }}
• cache_mode
  • cache mode
  • value: none, tool-cache or cache
  • default: cache
  • tool-cache
    • using: @actions/tool-cache
    • works in most cases with Self-Hosted Runner
  • cache
    • using: @actions/cache
    • works the same as actions/cache
• cache_prefix
  • if selected cache on cache_mode, option that prefix of cache key
  • Recommended use when parallel jobs
• install_root
  • if selected none or cache on cache_mode, use directory that dicide at this option
  • default: ${{ runner.temp }}

• installed_crystal_json
  • installed json that GitHub Release Asset
• installed_shards_json
  • installed json that GitHub Release

see Contributing.md