Address PR #1 review comments

[Copilot]

Addresses review feedback on PR #1 for the Agda setup action implementation.

Changes

• Imports: Use .Base submodules (Data.Bool.Base, Data.Nat.Base) in example workflow
• Checkout action: Update actions/checkout from v4 to v5 across all workflows and documentation
• Test workflow: Refactor from 4 separate jobs to single job with matrix strategy across platforms
• Documentation: Add periods to feature list items in README

Matrix Strategy

Consolidated platform testing:

jobs:
  test:
    strategy:
      matrix:
        os: [ubuntu-latest, windows-latest, macos-latest, macos-13]
        include:
          - os: ubuntu-latest
            agda-stdlib-version: '2.3'
          - os: windows-latest
            agda-stdlib-version: ''
          # ...
    runs-on: ${{ matrix.os }}

Original prompt

Please address the review comments in PR #1 and add a new commit fixing them.

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[andreasabel]

Great!