Add Support for Cache manifest in HTML5

[eliasjpr]

Description

Enable browser to cache assets using the Cache manifest in HTML5

The cache manifest in HTML5 is a software storage feature which provides the ability to access a web application even without a network connection. It became part of the W3C Recommendation on 28 October 2014.[1] This feature is in the process of being removed from the Web platform. Using any of the offline Web application features at this time is highly discouraged and use of service workers is recommended instead.

Read more https://en.wikipedia.org/wiki/Cache_manifest_in_HTML5

[AndiLavera]

Can you explain this? Add support for the a deprecated feature? It looks like MDN now recommends using service workers? https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API/Using_Service_Workers