Updated contact details table

README.md

@@ -14,6 +14,7 @@ tracker.
 | Yorick Peterse   | Mentor  | <yorick@gitlab.com>     | @yorickpeterse | @yorickpeterse | @YorickPeterse |
 | Grzegorz Bizon   | Coach   | <grzegorz@gitlab.com>   | @grzesiek      | @grzegorz      | @grzesiek      |
 | Tomasz Maczukin  | Coach   | <tomasz@gitlab.com>     | @tmaczukin     | @tmaczukin     | @tmaczukin     |
-| Piotr Szotkowski | Coach   | <chastell@chastell.net> | ...            | ...            | @chastell      |
+| Piotr Szotkowski | Coach   | <chastell@chastell.net> | ...            | @chastell      | @chastell      |
+| Tomasz Stachewicz| Coach   | <t.stachewicz@gmail.com>| ...            | @tomash        | @tomash        |
 | Ula              | Student |                         | @ubudzisz      | @ula           | @ubudzisz      |
 | Kasia            | Student |                         | @kradydal      | @kasia         | @kradydal      |