polishing credits section in the README

Author: slayoo

README.md

@@ -109,7 +109,7 @@ gdb python
 
 #### PyPartMC:
 
-author: [Sylwester Arabas et al.](https://github.com/open-atmos/PyPartMC/graphs/contributors)   
+author: [PyPartMC developers](https://github.com/open-atmos/PyPartMC/graphs/contributors)   
 funding: [US Department of Energy Atmospheric System Research programme](https://asr.science.energy.gov/)   
 copyright: [University of Illinois at Urbana-Champaign](https://atmos.illinois.edu/)   
 licence: [GPL v3](https://www.gnu.org/licenses/gpl-3.0.en.html)