There is a systemic way, but it applies to ALL typing, not just in Pages. Open System Preferences/Keyboard, and on the Text button there will be a place to insert a short version of what you want expanded. For example, I have "omw" set to expand to "On my way!" for use in Messages. Since I use iCloud to sync things, that lets me use the shortcut on my iPhone so that when I'm at a traffic light, three keys will send the message. You could, for example, use "jmy" to expand to be jermya. But remember, this is EVERYWHERE, not just in Pages.
There is a similar setting in Pages under Preferences, if you want to see if that works for you. The key is to have the replaced set of keys be something that you don't run into in regular words. You will have to experiment to see how it works.