docs: describe page last modification date (#562)

exampleSite/content/docs/guide/configuration.md

@@ -212,6 +212,22 @@ Options for `theme.default`:
 The `theme.displayToggle` parameter allows you to display a toggle button for changing themes.
 When set to `true`, visitors can switch between light or dark mode, overriding the default setting.
 
+### Page Last Modification
+
+The date of the page's last modification can be displayed by enabling the `params.displayUpdatedDate` flag. To use Git commit date as the source, enable also the `enableGitInfo` flag.
+
+To customize the date format, set the `params.dateFormat` parameter. Its layout matches Hugo's [`time.Format`](https://gohugo.io/functions/time/format/).
+
+```yaml {filename="hugo.yaml"}
+# Parse Git commit
+enableGitInfo: true
+
+params:
+  # Display the last modification date
+  displayUpdatedDate: true
+  dateFormat: "January 2, 2006"
+```
+
 ### Page Width
 
 The width of the page can be customized by the `params.page.width` parameter in the config file:

exampleSite/hugo.yaml

@@ -3,6 +3,7 @@ baseURL: "https://example.com/"
 title: "Hextra"
 
 enableRobotsTXT: true
+# Parse Git commit
 enableGitInfo: true
 # enableEmoji: false
 hasCJKLanguage: true
@@ -135,6 +136,7 @@ params:
     displayPoweredBy: true
     width: normal
 
+  # Display the last modification date
   displayUpdatedDate: true
   dateFormat: "January 2, 2006"