update FAQ for Using Hugo's Syntax highlighter "chroma"

content/posts/papermod/papermod-faq.md

@@ -274,16 +274,16 @@ Add `#center` after image to center align an image
 
 1. Disable Highlight.js in site `config.yml`
 
-```yml
-params:
+    ```yml
+    params:
         assets:
             disableHLJS: true
-```
+    ```
 
 2. Set hugo's markdown styling in site `config.yml`
 
-```yml
-markup:
+    ```yml
+    markup:
         highlight:
             # anchorLineNos: true
             codeFences: true
@@ -291,17 +291,19 @@ markup:
             lineNos: true
             # noClasses: false
             style: monokai
-```
+    ```
 
 3. If you want `lineNos: true`, the background won't be proper.
+   This will only work with `noClasses: false` or `pygmentsUseClasses: true`.
+   Read [Generate Syntax Highlighter CSS](https://gohugo.io/content-management/syntax-highlighting/#generate-syntax-highlighter-css)
 
-Add the following to `assets/css/extended/custom.css`
+    Add the following to `assets/css/extended/custom.css`
 
-```css
-.chroma {
+    ```css
+    .chroma {
         background-color: unset;
-}
-```
+    }
+    ```
 
 More Info : [Configure Markup - Highlight](https://gohugo.io/getting-started/configuration-markup#highlight)