Update CONTRIBUTING with default black line length (#45)

Author: garrison

CONTRIBUTING.md

@@ -16,7 +16,7 @@ Users are encouraged to use GitHub Discussions for engaging with researchers, de
 
 ### Project Code Style
 
-Code in this repository should conform to PEP8 standards. Style/lint checks are run to validate this. Line length must be limited to no more than 100 characters.
+Code in this repository should conform to PEP8 standards. Style/lint checks are run to validate this. Line length must be limited to no more than 88 characters.
 
 ### Pull Request Checklist