Once again though, this will not affect img tags already in content, though it will at least affect newly inserted old images. To alter existing content, you are better off running a one time script that seeks out img tags with no title attribute and updates the content to include them.

Note that title attributes have some accessibility issues. Depending on why you want them, there might be a better way. See https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/title#Accessibility_concerns