Add favicon for each site

[jgierer12]

Is your feature request related to a problem? Please describe.
Not a problem, just a neat idea I had to spice the site cards up a little: Add each site's favicon next to its title.

Describe the solution you'd like
This could be solved relative easily because Google has a favicon service. Just do an <img src="https://www.google.com/s2/favicons?domain={url}" />. Example:

<img src="https://www.google.com/s2/favicons?domain=https://webgems.io" />

=>

Describe alternatives you've considered
N/A

Additional context
N/A

[lostdesign]

Merged in #165