chore(index): improve installation guide formatting

Author: mehalter

src/content/docs/index.mdx

@@ -66,7 +66,7 @@ color support.
 
 <Steps>
 
-1. **Make a backup of your current nvim config** (if exists)
+1. **Make a backup of your current nvim config** _(if exists)_
 
    ```sh
    mv ~/.config/nvim ~/.config/nvim.bak
@@ -97,7 +97,7 @@ color support.
 
 <Steps>
 
-1. **Make a backup of your current nvim config** (if exists)
+1. **Make a backup of your current nvim config** _(if exists)_
 
    ```powershell
    Move-Item $env:LOCALAPPDATA\nvim $env:LOCALAPPDATA\nvim.bak