Perhaps you can simply import your entire website and then go through and group pages into sections.
I imported my website a long time ago so I don’t really recall the procedure, but you could search the forum for instructions. Here is one bit I found:
In 2020 Duncan wrote,
"You can use the “Import page” option under the Insert menu. This imports one page at a time.
From the new document template picker you can import a website published on the web. You can also enter a file:// address there, which is a bit tricky to construct.
If you need to import a whole site but from a disk location, I suggest opening the home page from the Finder in Safari, then copy/pasting the file:// address in Safari’s address bar into Sparkle’s new document sheet. This will import the whole site from the disk location."