Homepage cleanup for audit.

Homepage cleanup. Code looks good. Updated images to all be of the latest tools. Images figured, spans changed to kbd where appropriate, removed confusing links around images.

Hopefully this all works right, can't really test the index page locally. This is *mostly* just cleaning the code style up some. Minor grammar updates to drop some wordyness. And then ofc the updated images. Some are just renamed since I realized in looking things over I was being served incorrect images.

The biggest thing that could be off worry here is I dropped the breakpoint links. Since it isn't being produced anymore I don't really see mentioning it being a big thing for the homepage.
Nope, just looked up the spec and it says to only use abbr the first time abbreviations are used. I'm removing all the duplicates now.