[Feature]: Gamma adjustment for TCD Sampler

[Aptronymist]

Feature description

per original docs value gamma should control the level of detail in output, yet I see no reference to that on huggingface

Edit: I actually found reference to it here, I knew there was something... it's apparently mapped to ETA? 0.3 default.
link

[vladmandic]

tcd maps gamma param to existing eta param as eta is otherwise unused. as such, its already supported.
and yes, if not present in configuration it will use 0.3 as default.