Update README.md

Author: sash-ko

README.md

@@ -35,13 +35,13 @@
 - Install [zsh-autosuggestions](https://github.com/zsh-users/zsh-autosuggestions):
   ```
   git clone https://github.com/zsh-users/zsh-autosuggestions \
-    ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-autosuggestions
+    ~/.oh-my-zsh/custom/plugins/zsh-autosuggestions
   ```
 
 - Install [zsh-syntax-highlighting](https://github.com/zsh-users/zsh-syntax-highlighting):
   ```
   git clone https://github.com/zsh-users/zsh-syntax-highlighting.git \
-    ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting
+    ~/.oh-my-zsh/custom/plugins/zsh-syntax-highlighting
   ```
 
 - Copy `starship.toml` to `~/.config/`