Add zero_point_shift to 1.0.0 encoding spec documentation

Signed-off-by: Kyunggeun Lee <kyunggeu@qti.qualcomm.com>

Author: kyunggeunlee

Docs/techniques/encoding_spec.rst

@@ -301,7 +301,7 @@ Certain keys will only be present for certain quantization types, as indicated i
      - X
    * - bw
      - uint8
-     - Encoding bw (>=4 and <= 32)
+     - Encoding bw (>=2 and <= 32)
      - X
      - X
      - X
@@ -327,6 +327,13 @@ Certain keys will only be present for certain quantization types, as indicated i
      - X (INT only)
      - X (INT only)
      - X
+   * - zero_point_shift
+     - float32[]
+     - Flattened array of fractional zero point shifts for int2 quantization
+     - X (INT only)
+     - X (INT only)
+     - X (INT only)
+     - X
    * - compressed_bw
      - uint8
      - Compressed bw