'leaning tower of macros' slides link broken

Stream: lean4 dev

[Alok Singh]

https://lean-lang.org/talks/RacketCon2022.pdf is a broken link now, but I refer to it a lot, especially the slide showing the whole tower from infixl -> notation -> macro -> syntax/macro_rules -> elab_rules

[Chris Henson]

Wayback machine has an archive: https://web.archive.org/web/20250207230840if_/https://lean-lang.org/talks/RacketCon2022.pdf