docs: add Emma Twersky to DevRel Contributor page (angular#38084)

This commit adds Emma Twersky to the Angular Contributors page along with a bio & a photograph.

PR Close angular#38084

Author: twerske

aio/content/images/bios/twerske.jpg

@@ -824,5 +824,14 @@
     "twitter": "ahasall",
     "website": "https://www.amadousall.com",
     "bio": "Amadou is a Frontend Software Engineer from Senegal based in France. He currently works at Air France where he helps developers build better Angular applications. Passionate about web technologies, Amadou is an international speaker, a technical writer, and a Google Developer Expert in Angular."
+  },
+  "twerske": {
+    "name": "Emma Twersky",
+    "picture": "twerske.jpg",
+    "twitter": "twerske",
+    "website": "http://twerske.github.io",
+    "bio": "Emma is a Developer Advocate at Google. She is passionate about good user experiences and design.",
+    "groups": ["Angular"],
+    "lead": "mgechev"
   }
 }