feat: add Homebrew formula for dbx-cli

docs/content/docs/cli.mdx

@@ -7,10 +7,19 @@ description: Use DBX connections from terminals, scripts, CI, and Codex.
 
 ## Install
 
+### npm
+
 ```bash
 npm install -g @dbx-app/cli
 ```
 
+### Homebrew
+
+```bash
+brew tap t8y2/dbx
+brew install dbx-cli
+```
+
 Requires Node.js 22.13.0 or newer.
 
 Check the installed version: