Add accessibility (#753)

Given a pre-computed travel cost matrix and a land use dataset (containing the location of jobs, healthcare and population, for example), the package allows one to calculate accessibility levels and accessibility poverty and inequality. https://github.com/ipeaGIT/accessibility

README.md

@@ -698,6 +698,7 @@ energy system designs and analysis of interactions between technologies.
 - [EV2Gym](https://github.com/StavrosOrf/EV2Gym) - A V2G Simulation Environment for large scale EV charging optimization.
 - [Tools for the iTEM databases](https://github.com/transportenergy/database) - Contains tools for two databases maintained by iTEM, the International Transport Energy Modeling consortium.
 - [Cartes](https://github.com/laem/cartes) - A French alternative to Google Maps that aims to focus on climate-friendly transports mode.
+- [accessibility](https://github.com/ipeaGIT/accessibility) - Given a pre-computed travel cost matrix and a land use dataset (containing the location of jobs, healthcare and population, for example), the package allows one to calculate accessibility levels and accessibility poverty and inequality.
 - [FAF5-Analysis](https://github.com/mcsc-impact-climate/FAF5-Analysis) - Produce and interactively visualize publicly available geospatial data to support trucking fleets in navigating the transition to alternative energy carriers.
 
 ### Production and Industry