Yes it can be done, but with WEB edition you have no control over the HTML Source...
You need to add this manifest to the <html> tag as an attribute.
Without control over the content this can't be done.
Here is a working demo for a simple html content document:http://www.w3schools.com/html5/att_html_manifest.asp
Don't forget that RS WEB edition is all about "execute all code on the server side"...
And caching is like "work offline", which in WEB Edtion's case won't work eighter.
You can however create a "offline" part and point to it.