transformers gguf merge mergekit lazymergekit Casual-Autopsy/L3-Umbral-Mind-RP-v1.0-8B en base_model:Tremontaine/L3-Umbral-Mind-RP-v1.0-15B base_model:quantized:Tremontaine/L3-Umbral-Mind-RP-v1.0-15B endpoints_compatible region:us imatrix conversational