Fix links in intermediate app archetype section (#873)

docs/chapter1/intermediate/app-archetype/extract-styles.md

@@ -4,7 +4,7 @@ Application Archetype supports multiple styles, such as pure CSS, [CSS-Modules +
 
 ## Flags
 
-> Note: You can check how to customize the configs [here](/chapter1/intermediate/app-archetype/customize-config.md#extending-webpack-configurations).
+> Note: You can check how to customize the configs [here](./customize-config.md#extending-webpack-configurations).
 
 - `cssModuleSupport`: A flag to enable `css-modules + css-next` support.
 - <span style="color:red">**[Deprecated Warning] This is not a recommended set up.**</span> `cssModulesStylusSupport`: A flag to enable `stylus` support with CSS modules. (Default: false)
@@ -26,4 +26,4 @@ Without specifying flags, the following are the default cases for styles:
 - To use Stylus along with CSS-Modules + CSS-Next, include `*.styl` to your styles folder and set `cssModuleSupport` to true.
 
 - To use SCSS, include `*.scss` to your styles folder. Set `cssModuleSupport` to true OR leave it undefined.
-- To use SCSS along with CSS-Modules + CSS-Next, include `*.scss` to your styles folder and set `cssModuleSupport` to true.
+- To use SCSS along with CSS-Modules + CSS-Next, include `*.scss` to your styles folder and set `cssModuleSupport` to true.