[BUG] Incorrect formula in description of getSmallDependenceEmphasisFeatureValue()

[LouiseBloch]

The getSmallDependenceEmphasisFeatureValue() function appears to have a discrepancy in its documentation and implementation (the implementation appears to be correct). In the documentation (https://pyradiomics.readthedocs.io/en/latest/features.html#module-radiomics.gldm), the formula for this function squares the grey level value i. Based on the function name and implementation, it should square the run length j instead.