Add Antonin to Core Team section (#398)

* Add Antonin to Core Team section

* Remove social link

Co-authored-by: antonin <antonin.klopp-tosser@gmail.com>

Author: danielcaldas

README.md

@@ -144,10 +144,10 @@ const onNodePositionChange = function(nodeId, x, y) {
 
 The group of maintainers driving the project.
 
-| [Daniel Caldas](https://github.com/danielcaldas)                                                                        | [Sara Hernández](https://github.com/LonelyPrincess)                                                                       | [Terahn Harrison](https://github.com/terahn)                                                                      |
-| ----------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------- |
-| ![danielcaldas](https://avatars2.githubusercontent.com/u/11733994?s=120&u=e6b6edacde9c76844785e21d0568a4ba7c7f9aa4&v=4) | ![LonelyPrincess](https://avatars3.githubusercontent.com/u/17673317?s=120&u=d3170de2d3d4adf6268b892213927c8439d2f513&v=4) | ![terahn](https://avatars2.githubusercontent.com/u/23760949?s=120&u=9182d8d602285c507a1e88a0629785323b2f8703&v=4) |
-| [@\_danielcaldas](https://twitter.com/_danielcaldas)                                                                    |                                                                                                                           |                                                                                                                   |
+| [Daniel Caldas](https://github.com/danielcaldas)                                                                        | [Sara Hernández](https://github.com/LonelyPrincess)                                                                       | [Terahn Harrison](https://github.com/terahn)                                                                      | [Antonin Klopp-Tosser](https://github.com/antoninklopp)                                                            |
+| ----------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------ |
+| ![danielcaldas](https://avatars2.githubusercontent.com/u/11733994?s=120&u=e6b6edacde9c76844785e21d0568a4ba7c7f9aa4&v=4) | ![LonelyPrincess](https://avatars3.githubusercontent.com/u/17673317?s=120&u=d3170de2d3d4adf6268b892213927c8439d2f513&v=4) | ![terahn](https://avatars2.githubusercontent.com/u/23760949?s=120&u=9182d8d602285c507a1e88a0629785323b2f8703&v=4) | ![antonin](https://avatars2.githubusercontent.com/u/26838971?s=120&u=e3767df46ed6d7ef40d95562450d96a6bac5c437&v=4) |
+| [@\_danielcaldas](https://twitter.com/_danielcaldas)                                                                    |                                                                                                                           |                                                                                                                   |                                                                                                                    |
 
 ## Contributions