Add renovate configuration

[stevendborrelli]

Description of your changes

Includes an initial renovate configuration for the project.

Fixes #

I have:

• Read and followed Crossplane's contribution process.
• Added or updated unit tests for my change.

[Copilot]

Pull request overview

This PR adds an initial Renovate configuration to automate dependency updates for the Crossplane Function SDK for TypeScript project. The configuration is designed to group related packages, automerge non-major updates after a stabilization period, and handle security vulnerabilities automatically.

Changes:

• Added renovate.json with automated dependency update configuration including grouping rules for TypeScript, ESLint, testing, gRPC, and protobuf packages
• Configured automerge for non-major updates with a 14-day minimum release age
• Set up weekly scheduling and PR rate limits to avoid overwhelming the project

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[Copilot]

The automerge configuration for non-major updates doesn't explicitly require status checks to pass before merging. This means renovate could merge updates even if CI tests fail. Consider adding "platformAutomerge": true along with branch protection rules that require status checks, or add explicit configuration like "automergeType": "pr" with "automergeStrategy": "squash" and ensure your repository has branch protection rules requiring CI to pass.