Installation:

Make sure ScriptHookRDR is installed
Extract achievementScriptRDR.7z to your Red Dead Redemption folder
Run the game

The trigger is NOT RETROACTIVE i.e. Achievements triggered before the script was added will not be added to the .json file.

Logging is currently done in "GameLog.txt" and it might/will keep logging iterately if the Achievement is passed. That is expected behavior as the trigger is running in the game. Logging will be removed when script is out of beta. When facing bugs/issues please attach the log file too.