The parameter `templateOverrides` allows the override of any template or partial with a custom implementation.

## Example:

package.json
```json
{
    "scripts": {
        "generate": "openapi --input ./spec.json --output ./generated --templateOverrides index:\"Hello World\" service:./templates/service.hbs"
    },
}
```

```typescript
const OpenAPI = require('openapi-typescript-codegen');

OpenAPI.generate({
    input: './spec.json',
    output: './generated',
    templateOverrides: {
        index: 'templates/index.hsb',
        service: 'templates/service.hsb',
    },
});
```