feat(blog): add LastUpdateAuthor & LastUpdateTime (#9912)

Co-authored-by: OzakIOne <OzakIOne@users.noreply.github.com>
Co-authored-by: sebastien <lorber.sebastien@gmail.com>

packages/docusaurus-plugin-content-docs/src/frontMatter.ts

@@ -4,7 +4,6 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
-
 import {
   JoiFrontMatter as Joi, // Custom instance for front matter
   URISchema,
@@ -12,17 +11,15 @@ import {
   FrontMatterTOCHeadingLevels,
   validateFrontMatter,
   ContentVisibilitySchema,
+  FrontMatterLastUpdateSchema,
 } from '@docusaurus/utils-validation';
 import type {DocFrontMatter} from '@docusaurus/plugin-content-docs';
 
-const FrontMatterLastUpdateErrorMessage =
-  '{{#label}} does not look like a valid front matter FileChange object. Please use a FileChange object (with an author and/or date).';
-
 // NOTE: we don't add any default value on purpose here
 // We don't want default values to magically appear in doc metadata and props
 // While the user did not provide those values explicitly
 // We use default values in code instead
-const DocFrontMatterSchema = Joi.object<DocFrontMatter>({
+export const DocFrontMatterSchema = Joi.object<DocFrontMatter>({
   id: Joi.string(),
   // See https://github.com/facebook/docusaurus/issues/4591#issuecomment-822372398
   title: Joi.string().allow(''),
@@ -45,15 +42,7 @@ const DocFrontMatterSchema = Joi.object<DocFrontMatter>({
   pagination_next: Joi.string().allow(null),
   pagination_prev: Joi.string().allow(null),
   ...FrontMatterTOCHeadingLevels,
-  last_update: Joi.object({
-    author: Joi.string(),
-    date: Joi.date().raw(),
-  })
-    .or('author', 'date')
-    .messages({
-      'object.missing': FrontMatterLastUpdateErrorMessage,
-      'object.base': FrontMatterLastUpdateErrorMessage,
-    }),
+  last_update: FrontMatterLastUpdateSchema,
 })
   .unknown()
   .concat(ContentVisibilitySchema);