Option to generatelatest-version.json for Updater on release

[joepio]

Hi there, thanks for maintaining this!

The Updater can use static JSON files hosted on github to let clients check where to download new versions. This action can create artifacts and host them on github. It seems possible that this action could create the static JSON files that point to these artifacts, too.

Example output JSON:

{
  "name": "v0.31.1",
  "notes": "My release notes!",
  "pub_date": "2022-04-01T19:25:57Z",
  "platforms": {
    "darwin": {
      "url": "https://github.com/joepio/atomic-data-rust/releases/download/v0.31.1/Atomic.Server_0.31.1_aarch64.m1.macbook.dmg"
    },
    "linux": {
      "url": "https://github.com/joepio/atomic-data-rust/releases/download/v1.0.0/app.AppImage.tar.gz"
    },
    "win64": {
      "url": "https://github.com/joepio/atomic-data-rust/releases/download/v1.0.0/app.x64.msi.zip"
    }
  }
}

Example tauri.conf.json:

    "updater": {
      "active": true,
      "endpoints": [
        "https://raw.githubusercontent.com/joepio/atomic-data-rust/master/desktop/latest-version.json"
      ],
      "dialog": true
    },

Is this already the case, and am I missing something, or is this a nice feature?

Seems pretty doable:

• Add a flag to the action to enable auto updates. Inform users that this entails creating a commit that updates / adds a file.
• By default, create a latest-version.json in the root directory after creating the artifacts, and link to the download URLs of the artifacts.

[joepio]

Probably relates to #108