Consider Open in Browser addon

What Tor Browser still lacks.

Have you ever been annoyed when you wanted to see a document and the download popup appears which forces you to select an external application to view it? This extension allows you to open the document directly in your browser.

https://addons.mozilla.org/en-US/firefox/addon/open-in-browser/

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information