Put logo in repositories

[satazor]

It would be awesome to have the project logo in the repositories.

Idea from @diasdavid

[satazor]

@acostalima could you take care of this? Also, it would be awesome to update the image on https://github.com/ipfs-shipyard/discussify-browser-extension because the UI is old. An alternative solution would be to use GIF, perhaps the one that Cristina produced.