Support for +kubebuilder:validation:Required and omitempty

The current code generates a ascii doc with the following
```
[cols="20a,50a,15a,15a", options="header"]
|===
| Field | Description | Default | Validation
| *`seg`* __string__ | Name of the SEG + |  | Required: \{} +

|===
```

`Required: \{}` must be changed to `Required: True/False`.