update readme

README.md

 # OA-armsim
 
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 OA-armsim is a python module to simulate synthetic forearm acoustic pressure maps.   
 The code here implements the acoustic map generation for the simulated cylinder dataset (SCD) presented in Lafci, B., Ozdemir, F., Dean-Bean, X.L., Razansky D., and Perez-Cruz, F. (2022). OADAT: Experimental and Synthetic Clinical Optoacoustic Data for Standardized Image Processing.