[Gen] Rename '_options' field to '_initializers'
[Gen] Rename '_options' field to '_initializers'

'Option' is too generic a name, and since these are ways to initialize data before parsing, 'initializers' seemed more appropriate
'_init' is also supported
'_options' is still supported for backward-compatibility reasons, though if there's also an '_initializers' field, that takes precedence

Didero/DideRobot