I had a similar idea to yours. My goal was to link the content of a PDF document with a note in Obsidian. I had decided to go the other way, i.e. to extract individual pages or sections from the PDF and include them in the note so that the note would serves as a bridge between the PDF and Obsidian.
Since Obisidian only supports rudimentary PDF documents so far, I have developed a plugin with which it is possible to embed parts of a PDF in a note.
You can find the link here: