Change for different macOS versions

Installing-ZSH.md

@@ -38,9 +38,16 @@ you _might_ be OK. Preferably newer than or equal to `5.0`.**
 brew install zsh
 ```
 To set zsh as your default shell, execute the following assuming a default install of Homebrew
+
+  > Latest Mac OS version:
+```
+chsh -s /usr/local/bin/zsh
+```
+  > Mac OS **High Sierra** and before:
 ```
 chsh -s /bin/zsh
 ```
+
 Assuming you have [Homebrew](http://brew.sh/) installed. If not, most versions of
 **macOS** ship zsh by default, but it's normally an older version.  Alternatively, you may
 also use [MacPorts](https://www.macports.org/)