Since this is no common question, there is no best practice for this.
As you aim to get the most lightweight version from the user’s perspective here is a wild idea:
- add a textbox to the page and give it a general class like for instance ‘helptext’
- add a nanoflow that checks if the currentuser is administrator. If not, do noting. If so, it finds the textbox, copies this to a second editable textbox and the administrator can modify and store her improved version of the text (in all used languages)
- in the backend, somehow using the SDK these modified texts are read and they replace the text in the textelement. And the new version gets deployed.
Another option is to have a look at the AppstorApp “Help Text Viewer”.