The Mozilla Developer Network (https://developer.mozilla.org) offers a wiki documenting basically everything that happens on the web (anything that's missing just hasn't been gotten to yet). We invite and encourage readers to become participants in the writing process by using whatever skills they have to the best of their ability.
When editing pages on MDN, at the bottom of the page is the revision comment box. This box is a place to jot down a quick note explaining the changes you've made, asking for a technical review if you've changed an article, or the like. Because the revision notes feature is are way down at the bottom of the page, most people don't use this field, even though they're supposed to.
The "MDN: Save With Comment Hotkey" add-on watches for you to press
Cmd-Opt-Shift-S on Mac OS X, or
Ctl-Alt-Shift-S on Windows or Linux. When you do, the typing cursor is activated in the revision comment edit box and the window is scrolled to be sure the box is on-screen.
With this add-on installed, hopefully new MDN contributors will find it easier to use the revision comment feature. Out of sight, out of mind. Probably the biggest thing we could do to resolve this permanently is to make it easier and more convenient to enter a revision note, in turn making our article histories more coherent.