Add Polo to "made with" page

[mrego]

No description provided.

[github-actions]

Preview link: https://servo.org/add-polo/

[mrego]

Please @Ranrar check that it looks good to you, thanks!

[Ranrar]

@mrego I think I will wait a little, I found out the lib I used was only for V0.0.1, and I am now writing my own GTK4 integration for V0.0.4, so I can get it to work cross-platform Linux and Windows + Polo is just one part of the software suite Marco, it's just the easy part to start with, because it is just a Markdown viewer. Let's keep this commit waiting a little longer, till I have a working application :)

[mrego]

Are you using https://github.com/nacho/servo-gtk ?
Seems that @nacho has been updating it with new Servo releases.

About the page, many of the things there are very experimental, but we can wait until you feel more confident about adding this.

[nacho]

@Ranrar any reason to write another GTK4 integration when servo-gtk is available? If something is missing I definitely would accept PRs. Thanks!

[Ranrar]

@nacho It is not another full GTK4 integration, but custom-made to my application, for rapid development and testing.

[nacho]

@Ranrar have you had any issues with servo-gtk or you just didn't try it?

[Ranrar]

@nacho I tried it, and it worked, but only for v0.0.1, I cannot remember why I decide just to do it myself. If you want, you can have a look at my code.