Make your awesome guide more Googlable

[marcosscriven]

I only found this excellent guide via someone else's blog. I'm no SEO expert, but I feel sure updating your index page at https://danielkeep.github.io/ would bring this much higher in the search for info on Rust macros.

I can't say strongly enough how helpful your explanation of exactly where in the compilation cycle macro processing actually fits, and your visualisations of it.