Sublime Merge documentation has example of Command Palette customization: here, but I can’t find anywhere a list of all available commands with their arguments. There are some commands in /opt/sublime_merge/Packages/Default.sublime-package/Default.sublime-commands but for most of them arguments are not specified. Also, there is no “git” command mentioned in documentation. So, I assume that this file doesn’t contain all available commands.
I think, it would be nice to add such information to documentation.