docs(config): enhance documentation for bundle targets, closes #3251

[lucasfernog]

What kind of change does this PR introduce?

• Bugfix
• Feature
• Docs
• New Binding issue #___
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change?

• Yes, and the changes were approved in issue #___
• No

Checklist

• When resolving issues, they are referenced in the PR's title (e.g fix: remove a typo, closes #___, #___)
• A change file is added if any packages will require a version bump due to this PR per the instructions in the readme.
• I have added a convincing reason for adding this feature, if necessary

Other information

[lucasfernog]

By default Tauri bundles for all available targets. Users can select a subset of bundles to generate via the targets config option or the bundles CLI argument. This PR changes the CLI to automatically add the updater target to the targets config array if the updater is enabled, keeping the CLI argument untouched to allow users to optimize tests and quick builds.

[lucasfernog]

We'll change this PR to be a documentation change instead to prevent confusion and changes involving the target list.