[delog.io] Preview support

delog.io now supports preview. When sharing a delog page on twitter, telegram, etc., users can preview it. For example, it is shown below.

twitter card

profile

I'm testing the feature, please comment if you find any bugs while using it.

Web3.0 blogging service

https://delog.io

Witness vote

@pishio https://vote.hive.uno/@pishio