Add code examples property to schema

It would be great (mostly for documentation generation) if the schema top-level could have an optional array of example model values. Something like:

```
{
"typeName": "Foo::Bar::Baz",
"properties": {
"someprop": {
"type": "string"
}
},
...
"templateExamples": [
{
"description": "A basic example",
"model": {
"someprop": "An example value"
}
}
]
}
```

Labels: enhancement

No source files, tests, or entry points are named in the issue. Start by locating the schema definition and its validation or serialization tests, then confirm how an optional templateExamples array should be represented and how documentation generation consumes it.

Written by the indexing model from the issue text.