Ability to specify which sections to keep

[stefanogermano]

Is your feature request related to a problem? Please describe.

Often you want to keep some sections but overwrite everything else.
This is not possible at the moment (except for some very specific cases).

Describe the solution you'd like

It would be useful a "exclude" (or "except for") option to use in combination with "rewriteAll", where you can specify all the section you do not want to be overwritten. That would be very flexible, and you would not have to implement all the combinations (of different sections).

So we could say something like -rewriteAll -exclude introduction-description-references, and this will keep the content of those sections (but it can also be used to exclude any other combination of sections).

Describe alternatives you've considered

I saw that there is an -excludeIntroduction option, but that is just for the "Introduction" section, and it seems to exclude completely the introduction (even in the index).
My proposal is to keep the content that is already there (i.e., not remove the section), and it is (obviously) more generic.