Version 2

New in this version:

1. Tool has been expanded from 2 to 4 impedance functions:
   Exponential
   Cumulative
   Gaussian
   Cumulative-Gaussian

2. two similar scripts available, one for time-based accessibility and on with specific parameters for pedestrian accessibility

3. The script has been reorganized, and all parameters need to be set by the user are now in the beginning of the code

Version 1.0

v1.0

Update README.md