fix(gen): fix template validation dates (#4709)

Author: SamyOubouaziz

docs/DOC_PAGE_TEMPLATE.mdx

@@ -6,10 +6,9 @@ content:
   h1: # Title of the page again
   paragraph: # One-sentence description of the page.
 tags: # enter tags here
-dates:
-  validation: 1970-01-01
-  posted: 1970-01-01
-  validation_frequency: 96
+# dates:
+  # validation: XXXX-XX-XX (Year-Month-Day format)
+  # posted: XXXX-XX-XX (Year-Month-Day format)
 categories:
   - # product category (e.g. compute, serverless, managed-databases, etc.)
 ---