Update description generating logic

[DenTray]

1. All type-related validation rules should be skiped
2. required validation rule should be skipped, it already mark field with * symbol
3. If there is no required or present validation rule - field should be marked as "Optional"
4. Description should be started from the annotation or attributes method (annotation will be prioritized)

[pirs1337]

@DenTray, you can test

[DenTray]

@pirs1337 I've a strange numbers after the update

[pirs1337]

@DenTray, ready for testing

[DenTray]

@pirs1337 looks good now, thanks!

[DenTray]

Released in 2.2 version