Revert "readme: add homebrew installation instructions"

Until we get notarization going, we shouldn't recommend using homebrew.
This was submitted by accident.

This reverts commit 99b661859fa3dfe0dcf2c95efc6cf77dfcf43d9e.
diff --git a/README.md b/README.md
index 5c9d797..9df90e9 100644
--- a/README.md
+++ b/README.md
@@ -25,14 +25,6 @@
 
 ## 📋 Quick Start
 
-### Install via Homebrew
-
-```sh
-brew install boldsoftware/tap/sketch
-```
-
-Update by running `brew upgrade boldsoftware/tap/sketch`.
-
 ### Install via GitHub Releases
 
 Grab the most recent [nightly release](https://github.com/boldsoftware/sketch/releases).