Day 50 — `pdftopng` works!

Today I created a test PR to replace ghostscript with pdftopng, and most tests passed! The ones that failed have coordinates hardcoded in them. I'll just need to add a small tolerance in that float comparison and everything should be good to go! Not quite, I need to build Windows wheels before I can add pdftopng to camelot.

Based on this bug (about ghostscript from conda-forge not containing libgs) that Jim Hall discovered, I updated the docs with instructions to install ghostscript using the system package manager, whether someone installs camelot using pip or conda. I also updated the checks section of the installation docs to see if libgs is installed correctly or not.

At the end of the day, I presented a short talk on curlyboi at the RC presentations!