Not "doesn't appear to" but "is known not to"; exactly the sort of information needed in an introduction
I don't yet know anything about it, but free applications software https://import.io/ claims to do just that.
Other tools that I have used to create a reasonable document from a Web site have to cope with the fact that there is too much stuff that is "rubbish" in a document, though needed in the site. For example, you can have both totally irrelevant stuff (banners etc. etc.) and essential information provided as a graphic; it would be exceedingly difficult to distinguish these automatically. I have made experiments using htttrack, an open-source, multi-platform, 32- and 64-bit program that allows you to download an entire Web site, and working from there. I didn't find it particularly useful; it just lets you do exactly what you can do on the site, but working locally. If you use it, be sure to get your parameters right; it is possible to set them so as to download the entire Internet, in which case you must be sure to have several yottabytes of storage space available.
I have also saved single pages (not entire threads) as text from a browser (different browsers produce different detailed text, try several; I think Opera was better than Firefox); this loses graphics information, of course. Or use a word processor (I use Libreoffice Writer, functionally similar to Microsoft Word); either save a page temporarily as a complete HTML page which you edit, or open it by opening the URL in the word processor. This requires a lot of cleanup, and can be problematical (pages can be exceedingly slow, or crash the software). (If importing into Writer, you need to delete all sections, delete comments, and edit links, breaking them all, so graphics are stored directly in the document, not as Internet links.)
For something like a mostly text forum, you can simply copy and paste each posting into your software (word processor document, spreadsheet), skipping some postings ("thanks"), and possibly inserting links to necessary graphics instead of including them in the document.
I haven't use import.io, but have tried all the other methods, always successfully but usually requiring unrealistic amounts of effort.