Docs Module: Cache Expiration Handling and Fallback Mechanism

[salihozkara]

When a document is in cache but the cache time has expired, it should be pulled from GitHub again. If there is an issue pulling the document from GitHub, the old cached version is used as a fallback.

To ensure users are aware of potential inaccuracies, we need to add a notification on the page indicating that the displayed document is an old example and may contain incorrect information.