I have updated the plugin and the guide for developing plugins. The new versions are in the first posting of this thread.
The new plugin has the following updates for correcting text that has been scanned in with issues:
1. Some regular expressions for correcting the formatting of ePub files have been updated and a new one for dealing with quotes that should not be together has been added. The plugin cannot deal with paragraphs that begin with multiple tags eg <p><b><i> - there are too many combinations for this and it would require many more regular expressions to fix.
2. A new function for fixing incorrect breaks in sentences at the end of paragraphs has been added. This function is not perfect and will not detect all line breaks. There is an option in the json file to use one of the regular expressions that will automatically join paragraphs without a full stop; if a full stop was missing the paragraphs will be joined regardless.
3. A function to give consistency to italicised text. Sometimes scanned files start/end italics inconsistently eg an opening quote may be in italics, and the closing quote may not. I prefer to have only text in italics so this function achieves that objective. It may be disabled by editing the json file
4. A function to replace HTML items eg — with a long hyphen. Again, this may be deactivated by editing the json file.
I have also produced the guide in Sigil format as requested. This has been attached tot he first post.