AO3-6628 Reorder font family names

[smclairecarden]

Issue

https://otwarchive.atlassian.net/browse/AO3-6628

Purpose

Changes the order of default fonts.

Testing Instructions

How can the Archive's QA team verify that this is working as you intended?

With this style rule, if you don’t have either Lucida Grande or Lucida Sans Unicode installed, but you do have GNU Unifont, GNU Unifont will be used for almost all of the text on the site.
GNU Unifont is a useful thing to have on your computer because it has a glyph for every codepoint in Unicode, but it is not a pretty font, nor a particularly legible one. It should only be used as a last resort.
It should be changed to 'Lucida Grande', 'Lucida Sans Unicode', Verdana, Helvetica, sans-serif, 'GNU Unifont' so GNU Unifont is only used for characters that don’t have a glyph in the preceding fonts.

If you have a Jira account with access, please update or comment on the issue
with any new or missing testing instructions instead.

References

No.

Credit

Claire Carden - she/her

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[sarken]

Looks good -- thank you! I just had one small change to request if you have a chance to address it, but if it's not fixed, it won't keep us from merging this when the time comes. (Unfortunately, our last deploy threw us a bit off track, so we're dealing with a bunch of high priority and overdue issues at the moment, so it might take a while to merge either pull request.)

Just a heads up that it looks like this and the issue for #4706 both had their Difficulty set to First Timers Only. We'll definitely keep both PRs open since they're done, but we ask that folks limit themselves to one First Timer Only issue -- it helps us make sure new contributors always have a few to choose from when making their initial pull request to the project. If you're still getting a feel for things, we also have issues with a Difficulty of Easy you can check out (you might need to be logged in to access that link).