I have been trying to find the best way to "scrape" web pages and stick them into a tiddler, and I came across something interesting. Excuse any profanity, as I just found this stuff and did not name it.
3. Enter the URL of the site you want to convert to markdown.
4. Cut and paste the markdown to a new Tiddler and change it's type to Markdown.
5. Save and enjoy
The images still link back to the original website. I haven't found a solution that will scrape images and put them in tidller and link to them.