This seems like the most basic task but I finally had to resort to writing every link structure combination I could conceive of (~10, in all) and copy my Resume.pdf file into multiple folders to figure out how to do this. In the end I put my Resume.pdf file in a folder titled static in my home folder. From there I added a link to the header.html file amongst the list of other navigation links as follows. The key part is that it have a leading forward slash after the baseurl - ”{{ site.baseurl }}/static/Resume.pdf”
<li class="inline-block">
<a
target="_blank"
class="align-middle link-primary mr-2 mr-lg-0 ml-lg-2"
href="/static/Resume.pdf"
>Resume</a
>
</li>
Also of note, you may want to include a target=”_blank” so that the PDF opens in a new tab instead of replacing your site in the browser.