SOME cards for default templates

[benjaoming]

Respectful of read permissions, we should add preview cards for Fediverse, Twitter, Facebook, LinkedIn etc.

The default image path could perhaps be read from a setting.

[oscarmcm]

@benjaoming do you refer here to the social media tags? https://css-tricks.com/essential-meta-tags-social-media/

[benjaoming]

@oscarmcm yes, this exactly 👍

[benjaoming]

The referenced guide is really well-written but it's from 2016, so there might be a more updated resource.

[teury]

It is something very easy to do, it is only to put the labels and put title, description and for the image you can extract the first image, if the user has uploaded images in the article with the image plugins.

[benjaoming]

@teury agreed 👍 a PR is definitely welcome 🦄 🌈