Add $schema to cgmanifest.json

[JamieMagee]

This pull request adds the JSON schema for cgmanifest.json.

FAQ

Why?

A JSON schema helps you to ensure that your cgmanifest.json file is valid.
JSON schema validation is a build-in feature in most modern IDEs like Visual Studio and Visual Studio Code.
Most modern IDEs also provide code-completion for JSON schemas.

How can I validate my cgmanifest.json file?

Most modern IDEs like Visual Studio and Visual Studio Code have a built-in feature to validate JSON files.
You can also use this small script to validate your cgmanifest.json file.

Why does it suggest camel case for the properties?

Component Detection is able to read camel case and pascal case properties.
However, the JSON schema doesn't have a case-insensitive mode.
We therefore suggest camel case as it's the most common format for JSON.

Why is the diff so large?

To deserialize the cgmanifest.json file, we use JSON.parse().
However, to serialize the JSON again we use prettier.
We found that, in general, it gave smaller diffs than the default JSON.stringify() function.

[JamieMagee]

@msoeken could you merge please, if you're happy with the changes? I don't have permissions in this repository.