Fix formatting of Method 4 in README

Author: Maxteabag

README.md

@@ -86,7 +86,7 @@ uv tool install sqlit-tui
 pip install "sqlit-tui"
 ```
 
-### Method 4: AUR (Arch Linux)
+### Method 4: 'aur'
 
 ```bash
 yay -S python-sqlit-tui