Annotate Node

The module allows for comments/corrections/annotations on each sentence or paragraph on static nodes. Comments/annotation/corrections will appear below the content to which they refer. If correction mode is enabled in the configuration, it will also display additions and deletions in green and red.

The module is not intended for nodes that will be edited again after receiving annotations. Adding additional paragraphs or sentences after annotations have been added will result in annotations being misplaced.

My suggestion to start is to use the Annotate Node content type first to see how it works. Then if you if you decide to use it change the configuration to one of your own content types. Otherwise you'll lose content if you ever decide to uninstall this module and the annotate_node content type is removed.

To set-up a content type other than annotate_node, just copy and rename the the file in /annotate_node/templates/node--annotate_node.html.twig. Rename this file to be node--your_content_type.html.twig. The content type also needs a body (must be the machine name) as a field. Set the config at admin/config/annotation-configuration.

The module has some limitations:
The module numbers each sentence or paragraph and allows annotations on each. It isn't intended to be used to annotate a node that is still being edited. Any changes to the document will mess-up the placement of the annotations.
While it provides the option to break up the text by sentence, it does so by looking for a period and checking spacing. This isn't always perfect.
If you change the settings to break text by paragraph to sentence of vice versa, the color coding of changes done by JavaScript will be messed up on previous comments.
The Javascript we are using to highlight additions and deletions in correction mode does not work with asian characters.
Finally, the comments are text only, html will be removed.