Updated the README with more comprehensive instructions & updated deprecated Actions

[campbell-lunar]

No description provided.

[dannytsang]

I can't comment on the action.yml changes but I like the updated README.

[nemchik]

I just went on an adventure setting up GitOps for my ACLs and found a number of tweaks to be beneficial. Here is the end result of what I did (explanations below).

name: Sync Tailscale ACLs

on:
  push:
  pull_request:
  workflow_dispatch:

jobs:
  acls:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Fetch version-cache.json
        id: fetch-old-version
        uses: actions/cache@v4
        with:
          path: ./version-cache.json
          key: version-cache.json-${{ github.run_id }}
          restore-keys: |
            version-cache.json-

      - name: Test ACL
        id: test-acl
        uses: tailscale/gitops-acl-action@v1
        with:
          # api-key: ${{ secrets.TS_API_KEY }}
          oauth-client-id: ${{ secrets.TS_OAUTH_ID }}
          oauth-secret: ${{ secrets.TS_OAUTH_SECRET}}
          tailnet: ${{ secrets.TS_TAILNET }}
          action: test

      - name: Deploy ACL
        if: github.event_name == 'push' && github.ref_name == 'main'
        id: deploy-acl
        uses: tailscale/gitops-acl-action@v1
        with:
          # api-key: ${{ secrets.TS_API_KEY }}
          oauth-client-id: ${{ secrets.TS_OAUTH_ID }}
          oauth-secret: ${{ secrets.TS_OAUTH_SECRET}}
          tailnet: ${{ secrets.TS_TAILNET }}
          action: apply

From the top:

• The on section has push and pull_request without any branch restrictions so that the test action can run on pull requests, and commits pushed to pull requests
• The workflow_dispatch trigger (in the on section) is added to allow ad-hoc running the workflow from the Actions page in the repository (handy to re-deploy without creating a new commit in the main branch)
• The Test ACL step is moved above the Deploy ACL step so that the changes are tested before being deployed (the test step runs in the main branch and in any pull request)
• The Deploy ACL step has an added condition if: github.event_name == 'push' && github.ref_name == 'main' so deploys only happen if a commit is pushed to the main branch (ex: after a pull request merges, or a direct push to the main branch)
• I also have both the API and OAuth lines in my example above (with the API lines commented out) but I think this PR having them separated and nicely explained makes perfect sense