Some repository URLs are not displayed correctly

Example: In https://constructs.dev/packages/cdk8s-image the repository field currently links to https://github.com/cdk/undefined.

In the actual repository, the [package.json](https://github.com/cdk8s-team/cdk8s-image/blob/f78fc04c92346b6ff180111da3110de41c7c3dc5/package.json) specifies the repository as "git@github.com:cdk8s-team/cdk8s-image.git".

To display the correct URLs, either Construct Hub (or JSII when generating assemblies, or both) need to correctly parse [Git URLs](https://docs.npmjs.com/cli/v8/configuring-npm/package-json#git-urls-as-dependencies) and [GitHub URLs](https://docs.npmjs.com/cli/v8/configuring-npm/package-json#github-urls).