With all the .pdfs online that students and teachers download and use regularly, I have had several questions lately about how to convert a .pdf into text that students can edit. Taking a .pdf and converting it to recognizable text is called "Optical Character Recognition" or OCR. There are lots of ways to do this. The good news is that Google Docs has some OCR capability.
For some files, you might have to use a Google Add-on. From within a Docs file, go to Add-ons - Get Add-ons. Or in Drive, go to New File, Connect more apps. Doc Hub is a good one to choose.
I have Doc Hub installed on my account, so if I Control-Click a file, I can convert any .pdf to editable text.
The process is pretty slick, and when I think how potentially expensive, messy, and inaccurate OCR was just a few years ago, it makes my toes curl.