[New Feature]: Allow Admins to change page name and description in link previewers

[tariqksoliman]

Checked for duplicates

Yes - I've already checked

Alternatives considered

Yes - and alternatives don't suffice

Related problems

When other services show expanded link previews, they see something like this:

MMGIS
A web-based mapping and localization solution for science operation on planetary missions.

The page name MMGIS gets updated through JS so it's not taking effect in such previews and the description is hardcoded.

Describe the feature request

Add ENVs to inject html.head.title and html.head.meta[content="description"] values.