feat: correct readme

Signed-off-by: kjuulh <contact@kjuulh.io>

README.md

@@ -8,9 +8,24 @@ Git Now is a utility for easily navigating git projects from common upstream pro
 
 ## Installation
 
-```bash
+### Homebrew
-cargo (b)install gitnow
 
+```bash
+brew tap kjuulh/tap https://git.kjuulh.io/kjuulh/homebrew-tap
+brew install gitnow
+```
+
+### Cargo
+
+```bash
+cargo install gitnow
+# or
+cargo binstall gitnow
+```
+
+### Setup
+
+```bash
 # You can either use gitnow directly (and use spawned shell sessions)
 gitnow