Wordpress-style <!--more--> tag?

Would it be interesting for users to be able to manually define the end of the excerpt by writing a `` comment in the file contents? Leave a thumbs up/ down to give feedback.

The issue names no file, test, or entry point; start by locating the plugin's existing excerpt extraction logic for HTML files. Done means users can place a marker in file contents to define the excerpt boundary, with behavior consistent with the existing extraction.

Written by the indexing model from the issue text.