How can I make a smart comment add a directive to the output?
### Summary

I want to be able to comment on a table with any type of custom directive `@pii` and have that show up on the schema generation side. 

I've tried multiple different approaches with a plugin, the closest I've gotten is to creating a directive in the schema, but I don't need that to happen as I stitch the schema into a larger one that has the directive defined. Really I just need to be able to tell the schema to take the comment of `@pii` and output it to the schema

```
function PIITag(builder: any) {
  builder.hook("GraphQLSchema", (schemaConfig: any, build: Build) => {
    return {
      ...schemaConfig,
      directives: [
        ...(schemaConfig.directives || []),
        build.newWithHooks(build.graphql.GraphQLDirective,
          { name: 'notPii', locations: ['FIELD_DEFINITION', 'OBJECT'], args: {} },
          { name: 'pii', locations: ['FIELD_DEFINITION', 'OBJECT'], args: {} }
        )
      ],
    }
  });
}
```
This doesn't lead to the desired output.

Desired output:

```
comment on function health_check() is E'@notPii true';
```

```
type Query {
  """
  Exposes the root query type nested one level down. This is helpful for Relay 1
  which can only query top level fields if they are in a particular form.
  """
  query: Query!
  healthCheck: Boolean @notPii
}
```

any help here would be appreciated
