newbie and very basic user, how can I preceed each commit message with file name?

[LERoscoe]

I am a very light user of Sourcetree, for hobby software only, but I have a couple dozen apps in my repository.  When I commit, I like to start the commit message with which app (filename) the change is for.  Custom Actions is very unclear to me., I couldn't understand how to use it.  Is there a simple way to always add the filename to each commit message?