With my earlier suggested workflow in mind (make the document you want to distribute as PDF first in your favorite piece of software and, when finished, convert it to PDF), I recently discovered the tool:
PanDoc.
This is pretty powerful software and has to be used with the commandline. It is able to convert almost anything, the link shows you a quite impressive graph with all the file formats you could be converting between.
Used it myself to convert a few extensive manuals in .DOCX format to convert them to a mediawiki page and that worked like a charm. Screenshot images inside these documents were not added directly, just links that allow you add them yourself quickly enough. An almost 400 page, mostly text, manual took about half an hour in total. Including adding some images and verification of errors in format/structure.
For "funsies" I also converted that manual to PDF, after adding a more comprehensive Latex engine (
MikTex) to PanDoc, which had a very satisfying result too. And it was a bit faster than what I usually do when creating a PDF from a manual written in .DOC/.DOCX format (loading up that manual in LibreOffice and use its default PDF converter to create the PDF).
With those experiences, I will gladly recommend this software to anyone who needs any type of document converted to anything.
PanDoc is open source and available for Windows, Linux and Mac. Also available as portable app. The MikText engine is also available as a portable app. Which is how I used them.
Now some do not like to work with the command line, so here is a link to a separate
GUI for the PanDoc software.