Discussion Forum Schema improvements

[dfabulich (Dan Fabulich)]

From the other thread:

@dfabulich

Y’all can check your Google Search Console report, but when I go to https://search.google.com/search-console/r/discussion-forum and check my forum, I see this:

Why items are invalid:

• Either “text”, “image”, or “video” should be specified
• Missing field “datePublished”
• Missing field “author”

Improve item appearance

• Missing field “url”
• Missing field “text” (in “comment”)

So there does appear to be more work to do here.

So, yes, “url” is optional, but there are actual genuine errors here, too.