Support preview of event pages in Mastodon, Facebook, Twitter, LinkedIn, etc.

[rolandturner]

Is your feature request related to a problem? Please describe.
When I share an EventYay event page to social media to encourage sign-ups, the social media site doesn't present a title, image, and description extracted from the page metadata, because there isn't any there.

Describe the solution you'd like
I'd like the metadata for event pages in EventYay to automatically include the relevant tags for all common social networking software so when the event page is shared, the social media site's link preview is attractively presented.

Additional context

• details for Mastodon
• details for Facebook
• details for Twitter
• details for LinkedIn