Plugin support

[yindia]

How to enable --enable_alpha_plugins in pipeline

#current behaivor 
kustomize build ${kustomize_build_dir} #currently what we are doing 

#expected behaivor
kustomize build --enable_alpha_plugins ${kustomize_build_dir} #what we need

[karancode]

@evalsocket it's nice.. will implement it soon (maybe by today/tomorrow). PS: PRs are welcome :)

[yindia]

@karancode We can also add auto plugin download in same flow

on:
  - pull_request
jobs:
  kustomize:
    name: 'Kustomize'
    runs-on: ubuntu-latest
    steps:
      - name: 'Checkout'
        uses: actions/checkout@master
      - name: 'Kustomize Build'
        uses: karancode/kustomize-github-action@master
        with:
          kustomize_version: '3.0.0'
          kustomize_build_dir: '.'
          kustomize_comment: true
          kustomize_output_file: "gitops/rendered.yaml"
          enable_alpha_plugins : false
          kustomize_plugins : ["plugin/someteam.example.com/v1/chartinflator/ChartInflator"]
        env:
          GITHUB_ACCESS_TOKEN: ${{ secrets.GITHUB_ACCESS_TOKEN }}```

[karancode]

Thank you @evalsocket for the issue, PR & the suggestion. 😃 For auto plugin download, let me log another issue!

PS : If you're using this actions, please drop a star 🌟

EDIT : I have checked out another release: v1.0.2