: add Homebrew install instructions to README.md

Closes #76
https://github.com/cuelang/cue/pull/76

GitOrigin-RevId: e74e67d5cf756de7895a60a51d5cf78b0fa101fb
Change-Id: I9de2f4daddd194740ab80d42efd952fd9507690b
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/2949
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/README.md b/README.md
index f44710d..4b8d79c 100644
--- a/README.md
+++ b/README.md
@@ -93,6 +93,12 @@
 
 ### Download and Install
 
+#### Install using Homebrew
+
+Using [Homebrew](https://brew.sh), you can install using the CUE Homebrew tap:
+
+`brew install cuelang/tap/cue`
+
 #### Install From Source
 
 If you already have Go installed, the short version is: