[DOC] Possible typos in fundamental_types.md document

[jc19chaoj]

Report incorrect documentation

Location of incorrect documentation https://github.com/NVIDIA/cutlass/blob/main/media/docs/fundamental_types.md#numeric-types

Describe the problems or issues found in the documentation

In the "Numeric Types" section:

mx_float6_t<float_e2m1_t> : Block scaled data type with signed e2m1 element type and float_ue8m0_t scale factor and vector size of 32. Correction: mx_float6_t<float_e2m1_t> -> mx_float4_t<float_e2m1_t>

nv_float4_t<float_e2m1_t> : Block scaled data type with signed e2m1 element type and float_ue8m0_t scale factor and vector size of 16. Correction: float_ue8m0_t -> float_ue4m3_t