Update docs/Support-Tiers.md

Co-authored-by: Ruoyu Zhong <[email protected]>

Author: MikeMcQuaid

docs/Support-Tiers.md

@@ -40,7 +40,7 @@ For Tier 1 support, Homebrew on Linux must be all of:
 - have a Linux kernel >= 3.2
 - if running Ubuntu, using an Ubuntu version in "standard support": <https://ubuntu.com/about/release-cycle>
 - installed in the default prefix (i.e. `/home/linuxbrew/.linuxbrew`)
-- running on a supported architecture (i.e. Intel x86_64 or ARM64/AARCH64)
+- running on a supported architecture (i.e. Intel x86_64 or ARM64/AArch64)
 - not building official packages from source
 - you have `sudo` access on your system