Add new `rawVersion` variable in `urlTemplate`

This release adds the {{rawVersion}} variable in urlTemplate when building the download URL. This is useful when the URL contains both the version with a leading v, and without.

For example: https://github.com/cuelang/cue/releases/download/v0.3.0-beta.5/cue_0.3.0-beta.5_Linux_x86_64.tar.gz

This tool can now be easily configured using the following template:

    steps:
      - uses: engineerd/[email protected]
        with:
          name: "cue"
          fromGitHubReleases: "true"
          pathInArchive: "cue"
          repo: "cuelang/cue"
          urlTemplate: "https://github.com/cuelang/cue/releases/download/{{version}}/cue_{{rawVersion}}_Linux_x86_64.tar.gz"
          version: "^v0.3.0-beta"
          token: ${{ secrets.GITHUB_TOKEN }}

Thanks to @jzelinskie for adding this feature!