Add Łukasz Sowa as an ambassador (#1620)

* Add Łukasz Sowa as an ambasador

* Adding Łukasz's discord

Author: luksow

_data/ambassadors.yml

@@ -46,3 +46,14 @@
   github: SethTisue
   mastodon: https://fosstodon.org/@SethTisue
   linkedin: https://www.linkedin.com/in/sethtisue/
+
+- name: Łukasz Sowa
+  description: Managing partner @ Iterators, organizer of ScalaWAW meetup, programme committee member of several Scala-related conferences, Scala open source contributor.
+  image: https://www.luksow.com/assets/img/me.jpg
+  city: Warsaw, Poland
+  discord: luksow
+  twitter: luksow
+  github: luksow
+  linkedin: https://www.linkedin.com/in/luksow/
+  mastodon: https://fosstodon.org/@luksow
+  meetup: https://www.meetup.com/ScalaWAW/