Add iq3_ks to constants.py (ikawrakow#606)

Co-authored-by: Iwan Kawrakow <iwan.kawrakow@gmail.com>

Author: ikawrakow

gguf-py/gguf/constants.py

@@ -1320,6 +1320,7 @@ class GGMLQuantizationType(IntEnum):
     IQ2_KT    = 153
     IQ3_KT    = 154
     IQ4_KT    = 155
+    IQ3_KS    = 156
     Q4_0_R8   = 202
     Q5_0_R4   = 206
     Q8_0_R8   = 208
@@ -1535,6 +1536,7 @@ def get_type(val: Any) -> GGUFValueType:
     GGMLQuantizationType.IQ2_KT      : ( 256,   68),
     GGMLQuantizationType.IQ3_KT      : ( 256,  100),
     GGMLQuantizationType.IQ4_KT      : ( 256,  128),
+    GGMLQuantizationType.IQ3_KS      : ( 256,  102),
     GGMLQuantizationType.Q4_0_R8     : (  32,   18),
     GGMLQuantizationType.Q5_0_R4     : (  32,   22),
     GGMLQuantizationType.Q8_0_R8     : (  32,   34),