AllowAutoTopicCreation does not exist in writer config, but only in the writer struct

[yogeshg]

AllowAutoTopicCreation to be introduced to writer config, and passed through to the writer itself.

Supporting documentation

// AllowAutoTopicCreation notifies writer to create topic if missing.
	AllowAutoTopicCreation [bool](https://pkg.go.dev/builtin#bool)

[yogeshg]

#1279 if this is desirable.