Fix issue with redirect pages

[jglovier]

I'm using the jekyll-redirect-from plugin to create URL redirects from pages that have been moved around over the years.

I'm also using an external_url technique that generates pages for redirection from some older site version URLs.

They are not all working as expected. 🤦 I think they were at some point, but no longer. 🤷 I'm not even sure lol.

At this point, the site just needs some cleanup, I think.

I also posted about this on the jekyll-redirect-from repo thinking initially the redirects weren't working maybe because of Netlify (literally just couldn't figure out why else), but got a great tip there from a maintainer about the conflict with my external_url technique.

Need to do a little more digging, but probably could just remove some of the redirects if not easily fixable.