Add Homebrew installation instructions to README and docs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: johnsideserf

README.md

@@ -18,6 +18,13 @@ A terminal-based Signal messenger client with an IRC aesthetic. Wraps [signal-cl
 
 ## Install
 
+### Homebrew (macOS)
+
+```sh
+brew tap johnsideserf/siggy
+brew install siggy
+```
+
 ### Pre-built binaries
 
 Download the latest release for your platform from [Releases](https://github.com/johnsideserf/siggy/releases).

docs/src/user-guide/installation.md

@@ -1,5 +1,15 @@
 # Installation
 
+## Homebrew (macOS)
+
+```sh
+brew tap johnsideserf/siggy
+brew install siggy
+```
+
+Pre-built binaries for Apple Silicon and Intel Macs. The tap is automatically
+updated on each release.
+
 ## From crates.io
 
 Requires **Rust 1.70+**.